206 CALIFORNIA ACADEMY OF SCIENCES. 



repose; posteriorly, between the widely separated middle 

 coxiM, it is scarcely at all produced, but is very broadly 

 arcuate, reflexed and far above and free from the long 

 truncate metasternal process; the entire mesosternum is 

 coarsely, stron^iy and densely granulose, forming a striking 

 contrast to the highly polished pro- and metasterna. 



The anterior and middle tarsi have each four distinct 

 joints, but the long, very slender fourth joints are provided 

 at base with a very small and ill-defined segment, which 

 renders the accurate determination of the structure a mat- 

 ter of great difficulty ^ 



EUMITOCERUS u. gen. (Tachyporini.) 



Head moderately deflexed; eyes adjacent to the prothorax; antennae long, 

 very slender, capillary, verticillate; two basal joints much more robust, first 

 slightly less than twice as long as the second; labrum very small, much wider 

 than long, arcuate anteriorly, strongly inflexed and hidden under the project- 

 ing clypeus; maxillary palpi long, filiform and slender; second joint long and 

 very slender, third obconical, scarcely more than two-thirds as long as the sec- 

 ond, fourth slender, finely acuminate, slightly swollen toward base, longer 

 than the third, much more finely and densely pubescent. Pronotal hypomera 

 extremely strongly inflexed, almost parallel with the dorsal surface; wide be- 

 hind, very narrow anteriorly. Elytra passing a little beyond the metaster- 

 num. Anterior coxae narrow, conical, convex anteriorly; posterior moderately 

 prominent, conical posteriorly, eraarginate externally; posterior femora and 

 trochanters attached at the apices, their point of insertion not at all concealed. 

 Ventral segments margined; sixth exposed dorsally. Tarsi five-jointed. In- 

 teguments asperate. 



It can be readily seen that Eumitocerus bears a great re- 

 semblance to Habrocerus, but differs from that genus in the 



^. — I cannot but agree with Wollaston in his statement (Cat. Can. 

 Col., p. 535, foot-note), concerning the difficulties of the tarsal system as 

 applied to the Aleocharini. In many of the minute species it is impossible 

 to determine the number of tarsal joints in such manner as to leave no doubt 

 in the mind of the investigator, because of the hairy vestiture and the ap- 

 parent division of the terminal joint in many cases, which, as I have before 

 remarked, may be indicative of a real division at an early period in the his- 

 tory of the species. The more the subject is investigated, the more apparent 

 is it that the division of the Aleocharini in accordance with the number of 

 tarsal joints, is neither scientific in indicating true affinities, nor practical in 

 its application. 



