A. M. Chickering.
A New Acanthoctenus (Araneae: Acanthoctenidae) from Jamaica, W. I.
Psyche 67:81-86, 1960.

Full text (searchable PDF, 428K)
Durable link: http://psyche.entclub.org/67/67-081.html

The following unprocessed text is extracted from the PDF file, and is likely to be both incomplete and full of errors. Please consult the PDF file for the complete article.

PSYCHE
Vol. 67 DECEMBER, 1960 No. 4
-
A NEW ACANTHOCTENUS
(ARANEAE : ACANTHOCTENIDAE)
FROM JAMAICA, W. 1.l
BY ARTHUR M. CHICKERING
Albion College, Albion, Michigan
About twenty-five species are known in this family and all have been assigned to the Genus Acanthoctenus Keyserling, 1876. These have been reported all the way from Mexico to Argentina. So far as I have been able to learn, however, no representative has ever been recorded from the West Indies. It is, therefore, of considerable in- terest to be abk to report that both sexes of what I am compelled to regard as a new species have been collected in several localities in Jamaica, W. I. A holotype male and an allotype female have been selected and are described in accord with my usual formula in this brief paper. These types are being deposited in the Museum of Com- parative Zoology at Harvard College, Cambridge, Mass. Genus Acanthoctenus Keyserling, 1876
Acanthoctenus remotus sp. nov.
(Figures 1-6)
Holotype male. Total length I I mm. (somewhat exaggerated be- cause of softened and stretched condition of the specimen in the region of the pedicel). Carapace 5.59 mm. long; 4.55 mm. wide opposite second coxae where it is widest; well rounded from opposite posterior eyes to posterior border; median longitudinal thoracic groove deep and long.
Eyes. Eight in three rows, two, four, two; essentially as in the Ctenidae (Fig. I). Viewed from above, both rows recurved; viewed 'Published with the aid of a grant from the Museum of Comparative Zool- ogy at Harvard College.
8 I
Pachc 67331-86 (1960). hup Wpsycht einclub org/67/67-08i.htd



================================================================================

82 Psyche. [December
from in front, anterior row strongly recurved, posterior row moder- ately recurved in order to produce the characteristic placement. Ratio of eyes AME :ALE : :PME :PLE = I~:IO : :22 :22 (measurements taken from borders of the corneas). A3IE separated from one an- other by about one third of their diameter, from ALE by slightly more than their diameter. PME separated from one another by about one third of their diameter, from PLE by a little less than their diameter. LE separated from one another by about twice the diameter of ALE (the corneas of these eyes are extended much fur- ther than usual). Central ocular quadrangle wider behind than in front in ratio of IO:~, wider behind than long in ratio of 25 :22. AME separated from PME by a little more than one third of their diameter. Height of clypeus equal to about the diameter of AME. The clypeus bears 17-18 long slender spines with one isolated on each side dorsal to the base of the cheliceral boss. Chelicerae.
Nearly perpendicular, slightly divergent, moderately robust. Basal segment 2.275 mm. long. With many long slender spinules extending forward from promargin and many long, curved, light colored hairs at distal end. Basal boss well developed. Fang moderately robust, fairly evenly curved ; with three promarginal teeth, the middle one the largest; with three retromai-ghal teeth of moderate size and gradually diminishing in size from near base of fang distally.
Maxillae. Nearly parallel, moderately robust, only slightly concave in distal half along lateral border. Only slightly more than twice as long as broad. With well developed scopula along medic-l border to distal tip. Serrula only moderately well developed along distal lateral corner. With many long slender and stiff bristles especially along lateral border.
Lip. Only a little longer than wide in middle; slightly concave along distal border; reaches only slightly beyond middle of maxillae. Sternal suture slightly procurved.
Sternum.
Subrotund; as wide as long; slightly pointed at posterior end which is not extended between fourth coxae which are separated by about one fifth of their width. Only slightly scalloped opposite the coxae. Moderately well supplied with slender stiff bristles. Legs. 1423. Width of the first patella at "knee" 345 mm., tibial index of first leg 6. Width of fourth patella at "knee" .780 mm., tibial index of fourth leg 8.




================================================================================

19601 Chickering - Acanthoctenus 83
Femora Patellae Tibiae Metatarsi Tarsi Totals (All measurements in millimeters)
I. 8.450
2.795
10.400 9.425
3.250
34.320
2. 7.475
2.600
7.280
7.930
2.795 28.080
3- 5.590
1.820
4.940
6.630
2.405 21.385
4- 8.190 2.275
7.150
9.230
3.315 30.160
Palp 3.120 1.300 1.625 -- 2.015 8.160
All trochanters slightly notched ventrally at distal border. Tarsi with two claws, each pectinate in a single row. Trichobothria ob- served on femora, tibiae, metatarsi, tarsi and on palps. The distribu- tion appears to be irregular, but this has not been carefully enough studied to warrant a precise statement.
Figures 1-6. External Anatomy of Acanthoctenus remotus. Fig. 1. Eye group of male; seen from in front.
Fig. 2.
First tibia; ventral view. Fig. 3.
Left palpal tibia; nearly dorsal view.
Fig. 4. Left palpal tibia1 apophysis;
lateral view. Fig. 5. Left palpal tibia and tarsus; nearly ventral view. Fig. 6. Ventral view of epigynum.




================================================================================

84 Psyche
[December
Spines. There are many prominent spines on the legs but those which seem to be the most distinctive are: First tibia with seven pairs of long, fairly robust, ventral spines (Fig. 2) ; first metatarsus with ventral spines 0-2-2-2-lr-lr-lp. Second tibia with ventral spines essen- tially as in first but with more irregularity; second metatarsus with spines essentially as in first but also with more irregularity. Third tibia with three pairs of these robust spines; third metatarsus with ventral spines 0-2-2-2. Fourth tibia with ventral spines 2-2-2 ; fourth metatarsus with four pairs of ventral spines very irregularly placed. Prolateral and retrolateral robust spines easily confused with ventral spines. Calamistrum apparently absent. Tarsal scopulae well de- veloped on tarsi one and two but less well developed on tarsi three and four. Metatarsal scopulae moderately well developed on meta- tarsi one and two but absent from three and four. All tarsi with well developed claw tufts.
Palp. Relatively simple; closely similar to that of A. spinigerus Kerserling from Central America. Details best shown in Figures 3-5. Tibia with robust distal retrolateral apophysis; with two long slender dorsal spines near proximal end and a similar prolateral spine near proximal end. Patella with dorsal spines as follows : 2-0-1 (extremely long and slender). Hairs on tibia extremely long and stiff. Abdomen. Somewhat ovate with widest part about one third of its length from posterior end; 5.85 mm. long and 3.575 mm. wide at widest part. With a pair of dorsal depressions a little behind the middle. With three pairs of spinnerets, all short but with anterior pair the largest and the middle pair the smallest. With cribellum obscure and poorly developed.
Color i,n alcohol. Carapace with a broad, median, nearly uniformly light stripe. On each side of the posterior half of the median thoracic groove there is an elongated dark spot. The whole area lateral to the median light stripe is brownish. Between the PLE there are four narrow stripes formed by light grayish hairs. The chelicerae are irregularly striped with brownish; in front at the outer proximal corner there is a narrow stripe of grayish hairs. Abdomen: the dor- sum is brownish, much lighter in the middle in the dorsal half. There is also a group of four light colored tufts of long hairs in the posterior quarter. The whole ventral area, sternum, and venter is uniformly yellowish. The legs are generally brownish dorsally and yellowish å´v-entrally




================================================================================

female allotype. Total length 15.08 mm., including the somewhat swollen bases of chelicerae; without the latter 14.625 mm. long. Carapace 6.1 I mm. long, 5.20 mm. wide at interval between second 'tween
and third coxae where it is widest; only slightly sloping from b- PLE to about the middle of the well developed longitudinal median thoracic groove from which position it descends steeply to posterior border.
Eyes. Arrangement as in male. Ratio of eyes AME :ALE : :PME : PLE 14 :I 2 : :20:23 (measurements taken from borders of corneal hypodermis). AME separated from one another by about five sev- enths of their diameter, from ALE by about 9/7 of their diameter. PME separated from one another by about their radius, from PLE by about their diameter. Laterals separated from one another by about the long diameter of ALE. AME separated from PME by the radius of the former. Central ocular quadrangle wider behind than in front in ratio of about 5 :3.5; wider behind than long in ratio of about 5 :4.5. Height of clypeus equal to about 17/14 of the di- ameter of AME. Clypeus with about 12 long slender spines. Chclicerae. Nearly perpendicular ; parallel, robust, moderately gi b- bous in front ; basal segment 2.6 mm. long. Basal boss well developed. With many stiff bristles in front. Fang and teeth along fang groove essentially' as in male.
Maxihe, Lib and Sternum. Essentially as in male. Legs.
1423. Width of first patella at "knee" .975 mm., tibial index of first leg 9. Width of fourth patella at "knee" .91o mm., tibial index of fourth leg I I.
Femora Patellae Tibiae Metatarsi Tarsi Totals (All measurements in millimeters)
Trichobothria observed on many segments of legs and palps but their exact distribution has not been determined. Calamistrum short and
near proximal end of fourth metatarsus.
Spines. First leg : femur dorsal 0-1-1-1, prolateral 0-1-1-0, retro- lateral 0- I- I -0-1 -I - I -0, ventral with numerous spines irregularly placed and difficult to describe significantly; first tibia with nine pairs



================================================================================

86 Psyche [December
of ventral spines; first metatarsus with five pairs of what may be termed ventral spines but most of them are moved into a somewhat lateral. position. The second tibia has seven pairs of spines and the second metatarsus five pairs, all similar to those on first leg. All legs are provided with numerous stout spines. The palpal claw is simple with four moderately robust teeth.
Abdomen. Regularly ovate; cribellum moderately well developed; clearly divided. Otherwise essentially as in male. Epigynum. Essentials as shown in Figure 6. Color in alcohol. Essentially as in male except as herein noted. Carapace more clearly striped than in male; on each side of the median light stripe there is a broad darker stripe and on each an additional light marginal stripe thus making five broad stripes on the carapace.
Type locality. Holotype male from St. Andrew, Upper Mountain View, January 15, 1950 (C. B. Lewis). Allotype female from St. Andrew, Cross Roads, December 3, 1950 (R. P. Bengr~). The fol- lowing specimens are also in the collection : One paratype male from St. Andrew, Upper Mountain View, May 15, 1950 (C. B. Lewis) ; one paratype female taken with holotype male; another female from St. Andrew, Upper Mountain View, February, 1951 (C. B. Lewis) and two females from St. Andrew, Half-Way Tree, October 18, 1950 (R. P. Bengry). The author of this paper took one immature female in Hope Gardens, near Kingston, June, 1954. BONNET, PIERRE 1957. ~ibli'o~ra~hia Araneorum. 2. Toulouse : Les Arti- sans de 1'Imprimerie Douladoure.
KEYSERLING, GRAF E. VON 1876. Ueber Amerik. Spinnenarten d. Unterord- nung. Citigradae. Verh. 2001. Bot. Ges. Wien. 26: 609-708. T. 7-8. F. 1-72.
ROEWER, C. F. 1954. Katalog der Araneae. Vol. 2. Bruxelles.



================================================================================