Ralph V. Chamberlin.
A Two-Eyed Spider from Utah.
Psyche 35(4):235-236, 1928.

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A Two-eyed Spider from Utah
A TWO-EYED SPIDER FROM UTAH.
BY RALPH V. CHAMBERLIN,
University of Utah, Salt Lake City, Utah. The highly interesting family Caponiidse includes two African species, representing the genera Caponia and Diploglyna, and about a score of American species representing five genera. The American species hitherto known occur in the West Indies, northern South America and Cent>ral America, and in the desert region about the Gulf of California from where the writer has described species of three genera,-Orthonops, Tarsonops and Nopsides.1 The genus Orthonops was established for the single species 0. overtus Chamberlin the type of which was taken on San Luis Island, Gulf of California; but in April, 1928, Mr. Willis J. Gertsch, as a member of a field party from the University of Utah, secured a female of a second species of this genus in the San Rafael Desert region of Emery Co., Utah. This species, which is described below, is the only member of the family to have been found north of Mexico. Like all other American members of the family, excepting Nopsides ceralbona Chamber- lin, this form has but two eyes, a feature not found in spiders of any other family. Along with other distinguishing peculiarities, the members of this family have all four spiracles leading into tracheal tubes, no book-lungs being present. Orthonops gertschi, new species.
Female.-Carapace uniform light orange color, sparsely clothed with black hairs of moderate length which are all weakly curved. The sternum similar in color or slightly paler and bearing similar but more numerous hairs. Chelicerse, labium and endites colored and clothed like sternum. Palpi yellow, the hairs, particularly on the tarsus more numerous, appressed. Legs clear yellow, clothed with dark hairs like those of palpi and carapace. Abdomen gray throughout, somewhat darker above, 'The Spider Fauna of the Shores and Islands of the Gulf of California, Proc. Cal. Acad. Sci., XI1 (4), No. 28, p. 597 et seq., 1924.



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236 Psyche [~ecember
subdensely clothed with dark, appressed hairs similar to those of other parts of the body but mostly shorter and finer. The
carapace depressed, the head region not set off by distinct furrows and no stria thoracica evident, subovate in outline; pars cepha- lica narrowed forward, with anterior corners widely rounded. Eyes on a somewhat darkened area; removed from anterior border of head, as viewed from above, by only slightly more than the length of the eye-row, though without measurement the distance appears greater; eyes circular, separated by less than their diameter, the light, pupillary areas separated in dorsal view by about their diameter. Labium rather broad, apically rounded; Endites rather long, bent over the labium and nearly. meeting in the middle line in front of it. Chelicerse with claws slender; upper margin of furrow with a low membrane over most of the length, the lower margin with a shorter but higher, distally rounded, membranous appendage. Sternum weakly convex, in outline subelliptic but more strongly narrowed cau- dad tjhan cephalad, the caudal end acute. Abdomen narrowly
elliptic or subfusiform, pointed at both ends. First and second
legs decidedly more robust than the third and fourth, but the fourth longer than the first.
All coxse moderately long, the first
and fourth longer than second and third. Paired claws of leg ,? with six long teeth in single series. Unpaired claw on all legs well developed, smooth and untoothed. The appendage at base of tarsi I and I1 elongate, narrowly oblong in outline but distally pointed and somewhat curved. In leg I trhe tarsus is clavately thickened distad; its distal division, exclusive of claws, about half as long as the proximal division. - Total length, 4.75 mm. Length of cephalothorax, 1.9 mm. ; width, 1.37 mm. Length of leg I (inclusive of coxa), 5.74 mm. ; tib. + pat., 1.9 mm.
Length of leg IV, 6.86 mm.; tib. + pat.
IV, 2.1 mm.
Locality.-Utah: Emery Co., San Rafael Desert at Straight Wash., April, 1928. Holotype, a female, in author's collection.



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