AMERICAN COLEOPTERA. 81 



longer than the second, conical slightly flattened, joints 4 — 10 tri- 

 angular as broad as long, joint eleven oval. Clypeus rounded in 

 front, without suture, concealing the labrum and mandibles. Mouth 

 parts as in Macropogon. Prosternum slightly prominent at tip but 

 not received by the mesosternum. Tarsi shorter than in 31acropogon 

 but similarly lobed. Claws simple. 



A. Tillosus n. sp. — Oblong, brownish piceous (but variable), sparsely 

 clothed with long brown erect hair. Head densely punctured. Thorax a little 

 broader than long, slightly narrowed in front, apex truncate, base and sides 

 feebly arcuate, disc moderately convex, coarsely and densely punctured. Elytra 

 broader at base than the thorax, sides slightly converging posteriorly, more 

 narrowed at apical fourth, disc moderately convex, striate, striae coarsely and 

 closely punctured, intervals very narrow. Body beneath paler than above, 

 coarsely but not densely punctured. Length .24 inch; 6 mm. 



The color is variable, my specimen is piceous with the head, thorax 

 and under surface somewhat paler, one in Mr. Ulke's cabinet has the 

 head and thorax ferruginous. 



Occurs in Middle California, Mariposa. 



While the form of this insect and most of its characters place it 

 near Macrojwgon and Dasi/pogon, it diifers essentially in the structure 

 of the antennae and the want of articulation between the pro- and 

 mesosternum. 



Tribe II. — Dascyllini. 



Mandibles and labrum at least moderately prominent, the latter not 

 retractile. Clypeal suture usually obliterated. Trochanters of anterior 

 and middle legs normal in size not elongate. 



These characters separate the present from the preceding tribe. 

 The posterior coxas are contiguous in Basci/Uus, Anorns and Arseopiis, 

 distinctly separated in Anchi/tursus, and merely slightly contiguous 

 in the others. 



In geographical distribution we find Odontonyx and Anchytarsus 

 represented each by one species in the Atlantic region, the other 

 genera are peculiar to the Pacific fauna and have one species each, 

 excepting Dascyllus with two. 



The following table will enable the genera to be recognized : 



Mandibles prominent, acutely margined above, rectangularly flexed at tip, 

 head not retracted. Thorax acutely margined. 



Tarsi simple, slender Stenocolus. 



Tarsi lobed beneath. 

 Anterior coxae separated by the prosternum and but very little more 



prominent than it Dascyllus. 



Anterior coxae prominent and contiguous Auoras. 



TRANS. AMER. ENT. SOC. VIII. (11) MARCH, 1880. 



