NORTH AMERICAN COLEOPTERA. 105 



Under the name manj'udcollis there have hitherto been placed all 

 the California Scyinna.^ with black elytra and pale thoracic sides. 

 My attention was first called to the peculiar structure of the first 

 ventral segment of the male by Mr. H. C. Fall, of Pomona, Cal., 

 and it is plainly evident that two species at least have been con- 

 founded. I kncnv of no means of sepai-ating the females excepting 

 that in the present species the legs are nearly always black, while in 

 the other they are either red or the tibise and tarsi are pale. 



I have chosen the name margbikollis for the above form rather 

 arbitrarily from the fact that it is inferril)le from the descriptions 

 that the legs are almost entirely black. 



Hab. California, extending from a little north of San Francisco 

 to Santa Barbara, Los Angeles ; Catalina Isd., San Diego and 

 Pomona. 



S. ai'delio n. sp. 



This name is given to those forms heretofore mixed with margini- 

 collis, and to which the detailed description of that will fully apply, 

 except as to the following details : 



The legs may be reddish yellow, or the tibise and tarsi alone of 

 that color ; sometimes the legs are entirely piceo-rufous. 



The male has the fifth segment feebly emarginate, the first seg- 

 ment at middle not tuberculate, but with an oval polished space at 

 the suture sharply limited by the close punctures around it. 



The variations are as in marginicollis, but specimens entirely black 

 are more numerous, and that,, too, among those with the palest legs. 



It is possible that there remain two species in the above aggregate, 

 but I am unable to separate them, but those forms with the entirely 

 rufo-testaceous legs are to be considered the typical forms. 



Tliere is still greater difficulty in separating the species from la- 

 ciistrU and tenebrosus than in the case of margbdcollk. In the 

 latter the male has the small tubercle of the first ventral segment. 

 In the present species the first ventral does not greatly differ from 

 the other two mentioned. In both these, however, the last segment 

 of the male is much more deeply emarginate, especially in lacustris. 



Hab. — British Columbia southward through Washington, Oreo-on 

 and California, eastward to Utah. Specimens have been seen from 

 Arizona, El Paso, Tex., and Calmalli Mines, Penins. Cal. 



S. lacustri»$ Lee— Broadly oval, convex, black. Head sparsely punctate. 

 Thorax narrowed in front, sides feebly arcuate, surface sparsely feebly punctate. 

 Elytra moderately, coarsely, hut not closely punctate ; prosternal carina? distinct, 



TRANS. AM. ENT. SOC. XXII. (14) MAY 1895, 



