1928 ] 
A Two-eyed Spider from Utah 
235 
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 Central 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. Chelicerae, 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, 
x The Spider Fauna of the Shores and Islands of the Gulf of California, 
Proc. Cal. Acad. Sci., XII (4), No. 28, p. 59 7 et seq., 1924. 
