672 



FAMILY XXXI. — BYRRHID/E. 



eoxal cavities open behind; hind coxte extending to the margin of 

 the body, transverse and dilated into a plate partly protecting the 

 hind thighs; tarsi short, five-jointed, last joint nearly as long as the 

 others united. 



The literature treating of the North American species is as 

 follows : 



LeConle.—' 'Synopsis of the Byrrhid* of the United States," in 



Proc. Phil.' Acad. Nat, Sci.. VII, 1854, 113-117. 

 Horn,— 1 ' Table of Species of Limnichus," in Bull. U. S. Geol. 



Survey, V, 1879, 514. 

 Casey.— "Limnichus," Synopsis of," in Ann. N. Y. Acad. Sci., 



V, 1890, 145-160. 

 Forty-six species, distributed among 11 genera, represent the 

 family in the United States. Of these 8 species, belonging to four 

 genera, have been taken in Indiana. 



KEY TO INDIANA GENERA OF BYEEHID.E. 



a. Head prominent ; mentum large, elongate, semi-elliptical, coarsely punc- 

 tate, entirely closing the mouth below. I. Nosodendron. 

 aa. Head retracted; mentum small, quadrate, largely exposing the base of 

 the maxilla?. . 



b. Antennae 11-jointed, clavate ; lower face or epistoma not distinct; size 

 medium, 5 or more mm. 

 a. Front tarsi only retractile. II. Cytilus. 



cc. All the tarsi retractile. Ill- Byrrhus. 



bh. Antenme 10-jointed ; epistoma corneus, separated by a fine suture; 

 size small, less than 3 mm. IV. Limnichus. 



I. Nosodendron Lat. 1807. (Gr-.-, "disease + tree. ") 



This genus comprises two oval, convex beetles, having the head 

 advanced in front ; mentum as described in hey ; antenna? 11-jointed, 

 situated under the side of head. They live beneath the bark of 

 trees. One of the two occurs in Indiana. 



1287 (3876). Nosodendron unicolor Say, Long's Exped. to St. Peter's Riv., 

 II, 274 ; ibid. I, 180. 

 Rounded-oval, strongly convex. Black, somewhat shining ; antenme pic- 

 eous. Above uniformly, rather densely and coarsely punctate, more spar- 

 ingly and coarsely beneath. Elytra not striate but with rows of short, 

 stiff, erect- yellowish hairs, plainly visible only in side light. Length 5- 

 5.7 mm. 



Lake, Putnam. Crawford and Posey counties; scarce. April 

 22-July 4. 



