agS ENTOMOLOGICAL NEWS. [November, 



Two Families of Spiders new to the United States. 



By Nathan Banks. 



The two families of Leptonetidae and Oonopidse, comprising 

 very small, pale-colored spiders, are best described by compari- 

 son. The cephalothorax is broad; the dorsal groove is indistinct 

 •or wanting; there are rarely any radial grooves; the eyes are but 

 six in number, or sometimes none; usually surrounded by a patch 

 •of black; the mandibles quite large and long, and with a long fang, 

 and with some stiff bristles or teeth on the superior margin. The 

 lip usually short, triangular, or broadly rounded; the maxillae are 

 inclined over the lip, but do not touch as in the Scytodidse ; the 

 sternum broad ; the legs quite long and slender, mostly destitute 

 of spines ; the abdomen more or less globose 



It is considered that the Oonopidae have four stigmata, or lung 

 openings, on the venter, and the Leptonetidae but two; but the 

 second pair is so indistinct as to be practically valueless as a 

 character; indeed, one genus, undoubtedly a Leptonetid, has 

 been described as having four stigmata. The Leptonetidae have 

 three claw^s to tarsi and the Oonopidae but two. A most useful 

 secondary character is that in the Leptonetidae; the first pair of legs 

 is longer and their femora stouter than the other pairs ; while in 

 the Oonopidae it is the fourth pair which is usually longer and 

 the femora much thickened. The eyes in the Oonopidae are 

 larger and more in one group than in the Leptonetidae. Some of 

 the Oonopidae have horny shields upon the abdomen, the Lepto- 

 netidae have always a soft body. In the Leptonetidae, as in the 

 Scytodidae, there is a little conical projection between the spin- 

 nerets, called the colulus; this is not present in the Oonopidae. 

 The cephalothorax in the Leptonetidae is generally highest at or 

 in front of the middle, while in the Oonopidae it is highest. behind 

 the middle and slopes to the clypeus. 



LEPTONETID^. 

 In the Proc. Ent. Soc. Washington, 1891, Dr. Marx described 

 from Keyserling's manuscript a little spider under the name of 

 Usofila gracilis. It was said to have four stigmata, and was 

 placed in the Dysderidae. Simon soon noticed that it was 

 allied to the Leptonetidae, and thought it was his genus, Psilo- 

 derces. I have lately seen a specimen and feel sure it is a Lepto- 

 netid and agrees with Simon's genus. I cannot see any stigmata 



