SYNOPSIS OF SPECIES OF LISTRUS 181 



and feebly arcuate to the apex, the latter truncate and scarcely narrower 

 than the pedunculate base ; apical angles very obtusely rounded ; lateral 

 serrules strong; disk somewhat finely but deeply and closely perforato- 

 punctate, the intervals flat and feebly, sparsely punctulate, only slightly 

 wider than the punctures ; rugose area in lateral fourth. 



Elytra oblong, two-thirds longer than wide, fully one-third wider than 

 the pronotum, parallel, parabolic in apical third ; humeri tumid and 

 prominent; punctures rather coarse, deep and sparse. 



Length, 3.2-3.8 mm. ; width, 1.2-1 .4 mm. 



Type locality. Napa County, California. 



In the Leng Catalogue of the Coleoptera of North America recently 

 issued, Motschulsky's Listrus tibialis has been given a regular place in the 

 arrangement of species. Casey was unable to identify it when he wrote 

 his revision of the genus Listrus Mots, in 1895. I have likewise failed to 

 recognize it up to the present time. Inasmuch as I have mentioned two 

 of Casey's species that I could not identify, it will be quite proper at the 

 present time to give the translation of Motschulsky's description, which 

 is as follows : 



53. Listrus tibialis Mots. Form elongate-subovate, rather convex 

 and shining; punctate and sparsely clothed with cinereous pubescence. 

 Color nigro-aeneous above, black beneath ; tibiae rufo-testaceous, labrum 

 and tarsi inf uscate ; antennae and femora blackish. 



Head between the eyes transversely carinulate, carinula strongly 

 shining. 



Pronotum transverse, narrowed anteriorly ; apical angles distinct, the 

 posterior angles rounded; sides subcrenulate and set with rather long 

 fimbriae. 



Elytra subovate and arcuately narrowed posteriorly; clothed with 

 cinereous pubescence. 



Measurements. Length, 1% 1.; width, % 1. 



Habitat. Ross (Sonoma County, California). 



It is hoped that the synoptical arrangement as given above will aid 

 the student in placing the several species of these pretty little melyrids. 

 There will be disappointment in its application, as there are yet many 

 species to be discovered, and these undescribed forms will unwittingly be 

 intermixed and referred to some of the species already named. The 

 selected characters are not as complete as I wish they were, for a con- 

 siderable per cent of the specimens studied were mounted in such a way 

 that it was impossible to see the antennae, metatrochanters or fifth ventral 

 abdominal segment. An attempt was made to remount some of the 

 specimens, but they proved too fragile and could not be properly manipu- 

 lated without destruction. So it was decided at the present time not to 



