AMERICAN COLEOPTERA. 267 



B. cavicolle n. sp. — Moderately elongate, riifescent, shining. Head 

 sparsely punctate. Thorax one-fourth broader than long, sides parallel, 

 sliglitly sinuate at middle, anterior and posterior angles rounded, margin 

 posteriorly very obsoletely bidentate, disc flattened, at middle rather broadly 

 concave and very sparsely punctate, at sides more densely and coarsely. 

 Elytra scarcely wider than the thorax, each longitudinally broadly impressed 

 near the suture, surface striate, striae with moderately impressed but not closely 

 placed punctures which become fiuer near the tip, sides with a few sparsely 

 placed punctures. Body beneath nearly smooth. First ventral segment very 

 sparsely and finely punctured, second, third and fourth each with a single row 

 of closely placed deep punctures, last ventral sparsely punctate. Pygidium 

 coarsely punctured. Length .09 inch; 2.25 mm. 



The concavity of the disc of the thorax, with its generally broader 

 form readily distinguishes this species. 



One specimen in my cabinet from Pennsylvania. 



ReTision of the ]VITIDi:i>ID^ of the United States. 



BY GEORGE H. HORN, M. D. 



Anterior and middle coxae transverse, the former not prominent, 

 posterior coxae flat. Antennae ten or eleven-jointed, capitate, straight. 

 Tarsi usually five-jointed, nearly always dilated, first joint as long as the 

 second ; rarely four-jointed Cijhocephalus or three-jointed Smicrips. 



The above short diagnosis sufficiently indicates the more important 

 and defining characters of the family. For a fuller exposition the 

 student is referred to the ''Classification of the Coleoptera of North 

 America." 



With the exception of the two genera above indicated the family is 

 quite homogeneous, including them as aberrant members there is no 

 more heterogeneity than is usual in almost every family of large size. 



Mr. Murray (Monograph, p. 224), is willing to exclude Ci/bocejihahis, 

 basing his views on the four-jointed tarsi, the form of the thorax be- 

 neath and finally the general appearance, "to my eye Cyhocephalus 

 wants this family resemblance." The first objection is certainly en- 

 titled to a little consideration, but we are not informed where the 

 genus is to be placed, if in a new family the precedent would require 

 numerous new families everywhere among the Coleoptera from the 

 Dytiscidce down. Tlie objection based on the structure of the thorax 

 beneath is not at all valid, as Cyhocephalus differs far less from 

 Amphicrossus or Cyllodes than these do from Nittdida. Eegarding 

 the lack of family resemblance I am unable to see any feature which 

 deserves more attention than another. PaUodes and Conofelus are 



