CALIFORNIA ACADEMY OF SCIENCES. 291 



joints in the anterior tarsus instead of four, it would ap- 

 proach Colusa very closely according to the description, but 

 would differ very decidedly in the structure of the mesoster- 

 num between the coxae. These genera are allied especially 

 in the structure of the prosternum. 



The scutellum in Colusa is composite in structure, the 

 central portion being triangular or parabolic with the sur- 

 face strongly and asperately punctate, the exterior portion 

 being in the form of a trapezoid with the sides nearly straight 

 and convergent posterior^, having the portion of its surface 

 without the central triangle perfectly smooth and highly 

 polished. This forms a convenient basis of classification, as* 

 in some species the triangle extends beyond the trapezoid 

 posteriorly, and in others is entirely included within its 

 limits. Dr. Le Conte has also made use of modifications of 

 the scutellum in his classification of the species of Falagria. 



The only species which I have seen are Californian, and 

 they appear to be rather numerous, though somewhat closely 

 allied, except grandicollis, which is quite aberrant in the form 

 of the head, in sculpture and in the very feeble constriction 

 of the abdomen toward the base. They live for the most 

 part in wet moss. 



The following table will serve to identify the species here 

 described: 



Head at least as wide as the pro thorax; elytral punctuation 

 coarse. 

 Central asperate portion of the scutellum not passing be- 

 yond the enclosing trapezoid. 

 Elytra o having the sides convergent posteriorly, but 



very slightly longer than the pronotum gracilis. 



Elytra quadrate, at least one-third longer than the prono- 



tnm eximia 



Central portion of scutellum projecting beyond the enclos- 

 ing trapezoid, the projecting portion being deflexed. 



Size large, 4.2 mm. ; elytral punctuation very dense valida. 



Size small, 2.6 mm.; elytral punctuation much more 



sparse exilis. 



Head slightly shorter and narrower than the prothorax; 



elytral punctuation extremely minute and dense grandicollis. 



