4 MEMOIRS ON THE COLEOPTERA 



finely, sparsely and unevenly; abdomen and the deep groove-like 

 sutures nearly as in nnicolor, the oblique depressions for the hind 

 tibiae much shallower and less abruptly limited but almost similar 

 in extent, the fine grooves for the tarsi wanting; legs nearly as in 

 unicolor but piceous in color, the antennae similar but piceous, with 

 the club alone ferruginous. Length 4.6-5.0 mm., width 2.6-2.9 mm. 

 California (Placer and Siskiyou Cos.). [Nosodendron californicum 

 Horn,- Tr. Am. Ent. Soc., 1874, p. 22} californicum Horn 



The mesosternum is nearly as in the Byrrhinae, except that the 

 median apical notch receiving the tip of the prosternum, is much 

 smaller and more angulate and the prosternum narrower and more 

 attenuate posteriorly; the facets of the eyes are almost perfectly 

 flat and denned only by a reticulation of very fine feeble lines. The 

 general surface of the elytra under high power is seen to be closely, 

 excessively minutely and evenly punctulate, the corresponding 

 surface of the pronotum being finely and feebly reticulate in un- 

 evenly wavy lines. 



The formation of the abdomen, and particularly the deep coarse 

 groove-like sutures, is very remarkable and significant, because 

 differences in the form of the abdominal sutures are valuable tax- 

 onomic characters in separating genera in the tribe Pedilophorini 

 of the Byrrhinae, and also since abdominal sculpture constitutes a 

 prominent point of difference between Byrrhus and the closely allied 

 Cytilus. Unicolor Say, is said by Dr. Sharp to belong to the sup- 

 pressed Dendrodipnis Woll., while californicum is a true Noso- 

 dendron. 



Subfamily BYRRHINAE. 



This subfamily is the largest of the four and also includes the 

 greatest development of bodily size, although there are some minute 

 forms also, such as Syncalypta spinosa Rossi. In North America 

 we have four tribal groups, definable as follows: 



Mesosternum rather broad between the coxae, with a broadly rounded 

 median emargination for the tip of the short and wide prosternal 

 process; mandibles not concealed in repose; elytra generally sparsely 

 and simply punctate as in Nosodendron and similarly never having 

 a trace of striation PEDILOPHORINI 



Mesosternum as in the preceding tribe; mandibles generally not concealed 

 in repose; elytra shining and very sparsely sculptured as in Pedilo- 

 phorini, but having fine striae which are feebly impressed and pecu- 

 liarly disposed, those toward the suture uniting posteriorly with the 

 sutural stria; legs more feebly retractile than usual, the abdominal 

 sutures straight; body small in size SIMPLOCARIINI 



