440 ENTOMOLOGICAL NEWS [Dec., *I2 



several short hairs and one rather long one; occiput convex, slight- 

 ly emarginate on each side where the occipital bands meet the margin. 

 Head widest across the trabeculae-like processes. 



Thorax long; prothorax trapezoidal, with diverging sides and 

 straight posterior margin ; a hair in each posterior angle and two 

 on the posterior margin. Metathorax shorter and broader than 

 prothorax with anterior angles broadly rounded, sides converging and 

 posterior margin concave; a short hair on the lateral margin and 

 two longer ones on each side on the dorsal surface ; also two near the 

 meson. Legs poorly developed. 



Abdomen subovate, widest at the second and third segments and 

 regularly diminishing to the seventh ; last segment protruding with 

 two rather long hairs and several shorter ones; also a row of prom- 

 inent hairs across each of the other segments, those in the mesal 

 region being more closely set. Color pale yellow. 



Female. Antennae short (Fig. 43), ordinary, with segments of 

 nearly equal length. Trabeculae-like processes longer and more acute 

 than in the male. Abdomen more developed, subquadrilateral ; widest 

 at second segment and diminishing slightly to the sixth, with seventh 

 segment narrowed and the last narrow, bilobed ; two chitinized hook- 

 like processes apparently arising from the sixth segment (Fig. 4b). 



Measurements: 9 .96; $ .So. Length Width 



Male Female Male Female 



Head 24 .26 .28 .32 



Thorax 14 .16 .24 .28 



Abdomen 42 -54 -36 40 



Trichodectes californicus Chapman. (PI. XX, Fig. 2). 

 With some hesitation I refer several specimens, male and 

 female, from Dipodomys merriami, a pocket rat (Arizona), 

 to this species. The females of the specimens in hand are 

 very similar to T. californicus, but have fewer hairs on the 

 thorax and abdomen, less than half as many in the case of the 

 metathorax. The male, which has heretofore been unknown, 

 differs greatly from the female in the shape of the head and 

 in the antennae. The temples are nearly square, with two 

 short broad spines on the posterior angle. The antennae are 

 very striking, being long enough to reach well back on to the 

 abdomen ; first joint large, deep set, a little longer than either 

 of the succeeding joints, with a prominent tooth-like appendage 

 midway on the inner side ; second and third joints long and 

 narrow and about equal in length; two short heavy tp^th and 

 several longer spines on the tip of the last segment (Fig. 2a). 



