TURUtJ
ElAINilElEEN LAUOS
The Nor"'.vegian Zoological Expedition
to the Galapagos Islands 1925, conducted
by Alf Wo lie b rok.
I.
Arachnida.
BY
N A'l'HAN
BANKS.
(2 Plates.)
he Arachnida collected by .M:r. ALF WOLLEBLEK on the Norwegian Zoological Expedition to the Galapagos Islands 1925
contains twenty-one species of spiders and one Solpugida. The
specimens were collected from August till December. The 'ekspedition of Stanford University visited the islands from January
till June, and that from the New York Zoological Society in
April, so it is not surprising that there is a difference in the
material. In the Norwegian collection there is almost a complete
absence of the Epeiridae which were so numerous in the previous collections. It is thus evident that a number of species
are seasonal.
The most remarkable feature of the collection is the occurrence of the genus Desis, and such a number of specimens of
the Solpugid, originally described from a solitary specimen. To
the genus Desis belongs a few (eight or ten) species of fairly
large spiders, long reputed marine.
They have usually been found on coral reefs or other fiats
exposed at half-tide, living in cavities near the tubes of a worm
(Lithodomus), which they web over to make a habitable home.
They are not able to live long in water. None, so far, have
been found on the American coasts. Several are known from
the Australian region, one from near the Malay Peninsula, and
two from South Africa; an allied genus occurs in the Mediterranean. The finding of a species in the Galapagos is in line
with the cases of the Phrynid, Charinus and the scorpion,
Hadruroides lunatus noted in previous collections. This is evi-
T
NATIIAN HANKS
dence that a part of the Galapagos fauna was derived from
ancient land masses connceting to Australia and 1\Ialaya. A large
number of the Galapagos spielers, particularly those that spin
webs, are the same or very similar to Central American forms;
these have doubtless reached the islands through some form of
migration. Several of them are species that have a wide distribution in the tropics, and may be expected on almost any island
with sufficient temperature. As to negative evidence it may be
noted there is still no Oxyopid from these islands, although they
are common in the tropics and on many islands. Almost all
the material was secured at Floreana (Santa Maria).
Scytodidae.
Loxosceles longipalpis BKS.
Several specimens, none quite mature from Floreana, Sept.
Scytodes longipes LucAs.
One from Chatham 28. Dec.; it has the large pale spot in
middle of the cephalothorax as in lwbraica, but the legs are
heavily marked.
Oecobiidae.
Thalamia nieborowskii KULCZYNSKI.
An adult male and an immature female from Floreana.
Though I have not a mature female I believe it is the
Costa Rican species, since it agrees closely in markings and
especially in the size of eyes. The male palpal organ has three
very large sharp-pointed dark processes, one from near base,
very broad at base (when seen from below), the others, one each
side near tip, that on outer side with a broader base, and near
the base of the inner one is a rounded black lobe.
Length of male 1.8 mm.
The genus Oecobius is readily divided on whether the P. S. E.
are much the largest; the typical species has the A. M. E. much
the largest, so for this section of parietalis, navus, nieborowskii
I would retain Thalamia, at least as a subgenus. The Omanus
maculatus KEYS. thus goes in Oecobius, and since there is an
earlier Oecobius maculatus SrMON (1870) I would rename the
Brazilian speeies Oecobius keyserlingi.
AHACHNIDA
273
Pholcidae.
8pcrmoplwra placens CAMBH.
Floreana, 2D. Oct., one male. Cambridge des<.;ribed a female
from Mexico which differs from 8. merirlionalis of the U. S. by
having the eye-groups much nearer to each other. This male
agrees with placens in the position of the eyegroups, so Itake
it to be that species. The male palpus which is figured differs
considerably from 8. meridionalis. The front femora are faintly
granulate below towards base, and the jaws have several teeth
on outer edge.
Clubionidae.
Aysha pacifica BKs.
Two males and an immature female from Florcana 1.-5. Oct.,
and 20.-30. Oct.
Corinna wollebceki sp. nov.
Cephalothorax and mandibles dark red-brown, legs a paler
more yellow brown, but femora of male about as dark as the
cephalothorax, abdomen dark brown to almost black, wenter
paler, sternum and lip red-brown, coxae yellowish; no spots nor
marks anywhere.
Cephalothornx broad and heavy as usual; clypeus a little
higher than the A. M. E. Eye-rows but little curved, P. M. E.
a bout two diameters apart, a little further from the nearly equal
P. S. E.; A. lvl. E. plainly larger than other eyes, less than diameter apart, about as close to the A. S. E., quadrangle of M. E.
nearly square. Jaws with six rather small teeth, in male with a
fringe of white hair on lower edge.
Sternum finely granulate, as also the lower side of the front
femora of the male. Tibia I with six pairs of spines beneath,
tibia II with five pairs, these metatarsi with two p~irs; hind
tibiae with fewer less regularly paired spines, tibia III with one
spine above toward tip.
l\Iaxillae of male hardly twice as long as the tip. The
abdomen of male shows a dorsal basal shield, very slender, triangular, and reaching to the middle. The epigynum shows on
posterior part two pale cavities, narrowly separated. :From above
NATIIAN HANKS
----·------------------·---·-·-~---·-··----·----·-----------
the tibia of male palpus shows a very large triangular process,
and lJelow several other processes; the stype of bulb fairly long
and slender, a triangular tooth near its base, and on other side
is a slender, c.urved hyaline stripe.
Length 0' 7 mm, ~ D mm.
From Chatham, 28. Dce., young from Florcana 14.-18. Aug.
It appears nearest to C. nervosa of Central America, but
the palpal style is longer, and the tibial proeesses somewhat
different. Type in the Oslo Museum, paratype in the Museum
of Comparative Zoology.
Aga!enidae.
Desis isolata sp. nov.
Cephalothorax and jaws reddish yellow, sternum a little
paler, legs and abdomen very pale, without marks; hair mostly
pale. Cephalothorax broad in front, a little longer than tibia I,
with a short, but distinet dorsal groove. Anterior eye-row a
little shorter than the posterior, both almost straight; A. M. E.
small, hardly diameter apart, fully twice as far from the larger
A. S. E.; P. M. E. about twiee their "diameter apart, and about
as far from the nearly equal P. S. E.; S. E. about equal in size
and less than diameter apart; quadrangle of 1\f. E. very much
broader behind than in front; a long bristle in front of the
A. M. E. Legs densely clothed with long hair, mostly eurved
toward tip, but some erect, all very fine; leg I without spines;
II with one at tip of tibia beneath, and several at tip of metatarsus; leg III with two at tip of tibia below, two at middle and
·several at tip of metatarsus; leg IV with two at tip of tibia
and one on inner side before tip, metatarsus with two near
middle and several at tip, the tarsi III and IV with several
pairs below.
The jaws (seen from side) are evenly convex above, of the
size and shape of other species; there are five teeth on inner
row, two on outer, the proximal one very small and remote
from the other; the sternum is one-fourth longer than broad;
the maxillae very long, and with a longer apical point than
AIL\CIINIDA
--··-··-------·-····----·-··------
ligun~d by Simon for maxillosa; each superior tarsal elaw has
about six long teeth close together. The abdomen is densely hairy,
that on basal part is largely blackish, and much o[ it reeurved.
The vulva is rather more slender than some others that have
been figured, but of the same general shape.
Length 8 to 9 mm.
Two specimens from Floreana, 7. Sept., on the beach Type
in Oslo :I'I'lnseum, paratype in Museum of Comparative Zoology.
Therididae.
Theridion interruptunz BANKS.
A number of specimens from Floreana, 10. Sept.; 12.-14.
Nov.; 1.-10. Dec.; and Chatbam 28. Dec. The male was previously unknown.. The male by the palpus is related to the
males figured by Keyserling and Cambridge as T. albomacmlata
and T. rubicunda. The black spine at tip of the palpal organ is
longer than in those species; the cephalothorax is yellowish
brown to quite dark brown; the males have a black streak on
the femora as in these allied species. In none of the females
is the abdomen extended as in albomaculata; in the male the
abdomen is distinctly constricted a little above in the middle.
The marks on abdomen are variable, sometimes reduced to small
spots, but the one on pleura always shows, as well as that on
venter. Sometimes the two black stripes are connected instead
of interrupted in middle, this makes a narrow dentate stripe of
pale and silvery down the back. In all specimens the tip of
tibia I and IV is distinctly black, in many specimens there are
less distinct dark spots on tips of other tibiae, on the patellae,
and on tips of femora.
I think it extremely doubtful if the male figured by Keyserling and Cambridge is really the male of the original Crysco
albomaculata which is a very different spider from this Theridion. T. sexmaculatum and T. pusilla are probably closely
related, as also the recent T. delebile from Porto Rico.
Argyrodes jucundus CAMBR.
Several, Floreana 2. Aug., 29. Oct.
276
i\"\'l'llA;\1 BAi\KS
Lathrodel'tus upil'olis
BuTLEH.
Numrl'(J\!S specimens Floreana, Post Off. Bay 10, 11. Aug.
20.---30. Kov.
This is hardly more than a lo.eal \'ariety of L. mactans.
Epeiridae.
Argiope azgentata FAnR.
One very young specimen from Floreaua 39. Oct.; in previous collections it had been common.
Cyclosa cazulata HTZ.
One from Floreami, 3. Aug.
Gasteracantha insularis THoR.
Many speeimens 5. Aug. to 39. Oet.; on the last date some
young ones; also from Santa Cruz, 7. Aug.
Thomisidae.
Tmarus stolzmanni
KEYS.
Immature speeimens; previously recorded in other eolleetions, so probably this species. Floreana 39. Oct., 30.-30. Nov.
(nearly mature).
Sparassidae.
Selenops golopagoensis BKS.
From Floreana 1'.1:.--Hl. Sept., also Dec. (d'). The male was
previously unknown, so a figure of pal pus is given; the tibia has
the long slender process very similar to 8. mexicanus KEYS., at
its base, however, the small proeess is of a different shape; in the
palpal bulb the two long processes are shaq)pointed, and the
inner one much shorter than in 8. me.·ricanus, a plate near tip is
more deeply and sharply deft than in 8. mexicanus.
IIeteropoda venatoria LrNN.
Se\'Cral from Chatham, 38. Dec.
Ctenidae.
Odo ga lapagornsis BKs.
Se\'eral from Florcana, •L---8. Sept., 30. No\'. The male was
not previously known, al](l I figure the palpus, this is quite
<listinet from 0. insulan's BEs., on the outer side of the tibia
'J77
i,; a modillcd spinl'. The front lz>g·s have under tibia besides
the two pairs uf long· spines, a short apil:~il pair, two on each
c:,i(le, at1(l one :;huve toward tip; femur I has about eight spines,
one near base and one beyond middle abtwe the larger.
Lycosidae.
Lycosa snodgrassi
BKs.
One specimen, not quite mature, from Floreana Hi.-20. Sept.,
shore region.
Attidae.
Phyale bispinosa sp. nov.
Cephalothorax red-brown, with a broad band of white hair
on each side margin and a median stripe reaching up to the eyeregion, a spot of white hair below each A. S. E., clypeus with
long white hair extending clown over middle of jaws, rest of
ccphalothorax with yellowish hair. 1Iandibles reel-brown, with
white hair on outer sides; legs yellow brown, the anterior femora
darker, and these legs with much white hair beneath, the joints
often darker at tip, but not very plainly so. Sternum and coxae
yellowish; abdomen with a broad pale stripe in middle, broken
up toward tip, black on upper sides, and a broad black stripe
on venter.
There is a row of about 16 to 18 long stiff hairs across
head over the front eyes; eyes of second row about half way
between A. S. E. and third row; jaws with one tooth on hind
margin. Legs with many stout spines, each femur with one be-·
fore middle, two a little beyond and four in a transverse row
just before tip, three pairs under tibiae I and II, tibiae Ill and
IV .with one above at base.
The male palpus has on outer tip of tibia two long black
spines close together, the style is fine and starts at top of bulb.·
Length 5 to 8 mm.
A nearly full grown female has the abdominal marks as
in male, the ce1Jhalothorax pale, with the eyes on a dark band
extending back in a tlark stripe each side; the legs mostly pale.
From Floreana 1.--10. Oct., 20.---30. Oct. and young
+. ---8. Sept.
:\yt .\lng. f. :\atnn·. B. LXVJll.
19
278
Type in the Oslo "J[usrum, T'nratype in Museum of Comparative Zoology.
By the processes on tibia of palpus it appears rdaterl to
aralensis PECK. of (~<'niral Anwrica, but the marks arc different,
and that species has no spines above on tibiae ITI and IV.
Metacyrba hnmlaris BKs.
From Floreana 1.---10. Dee. The male has not be0n taken
\
before, in general structure and markings it is very similar to
the female, except that there are ·two pale parallel spines· on
dorsum of abdomen; the front tibia have two little spines on
inner side near tip, the .metatarsi also with two on inner side.
Philaeus pacificus BKs.
A male, Floreana, 10.-20. Oct.
So/pugida.
A mmotrcclw solitaria
BKS.
A number of specimens from Floreana, Post Off. Bay, during
Aug., Sept., and Dee. Both adults and young in Sept All were
on the shore region.
Printed, December 11th, 1930.
Nyt. 1\lag. f. Naturv. LXVIII.
PI. I.
Fig. 1. Metaeyrha insularis, palpus beneath. - Fig. 2. Metacyrba insularis,
palpus side. - Fig. il. Phyale bispinosa, palpus and tihia. - 4. Corinna
wollehaeki, palpus and tibia.
Fig. 5. O<lo galapagoensis, palpus. - Fig. G.
St'lrnops galopago,'nsi", palpus.
Jfiss E. B. Bryant <le/.
Nyt. Mag. f. l\'aturv. LX VUL
Pl. H.
4
jJ_
'
0
0
0
0 0
0
0
0
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~
Fig. 1. Theridion inlenuplum, alJdomen, three specimens, and vulva. - Fig.
Thcridion interruplum, palpus. -- il. Spcrmophora platens, palpus above.
Fig. 4. Desis isolata, jaw and ntlva. - Fig. i\. De,is isolala, eyes. - Fig.
Spermophora plaeens, palpus, side. - Fig. 7. 'l'halamia niellorowskii, palpus.
Fig. 8. Thalamia nil'lJOro\l'skii, <.>yes, anll l'Cphalothorax.
JJ1ss g
B. Bryant del.
2.
G.
-
0
