34 Journal New York Entomological Society, [voi. vil 



cept ge/m'ua, and cubcccola ; the former is much smaller and has dif- 

 ferent antennae, and the latter is different in every respect. Following 

 Horn's description I have placed cribricollis among those species hav- 

 ing the last ventral unmodified, but a specimen in my collection which 

 almost surely belongs here, has a well-defined thick sub-apical crest. 

 Length, 8-10 mm., .32-. 40 inch. 

 Habitat: Texas. 



A. quadrivittata Horn, Trans. Am. Ent. Soc, VII, p. 23, PI. I, 



Fig. 37- 



Cannot be mistaken for anything else. The yellow vittre are often 

 so broad as to leave only the suture and a narrow stripe beginning at 

 the humeral umbone dark. The thorax is always distinctly shining 

 with the punctures on the disk well separated. Length, 4- 5-5- 5 mm., 

 . 1 8-. 22 inch. 



Habitat : Occurs from El Paso, Texas, to the Mojave Desert in 

 California. 



A. insignis Horn, Proc. Cal. Acad Sci., IV, p. 377. 



Our tiniest species. The type is the only specimen known. 

 Length, 4 mm., .16 inch. 



Habitat : Lower California (San Raymundo) ; on cactus. 



A. gemina Horn, Trans. Am. Ent. Soc, VII, p. 23, PI. I, Fig. 



37 ; nebulosa Horn, Proc. Cal. Acad. Sci., IV, p. 376. 



I have been quite unable to discover characters which will permit 

 the retaining of nebulosa as distinct from gemina. The only differ- 

 ences mentioned by Horn are those of size and markings, both of which 

 are of no value whatever, as is amply shown by the dozen or more ex- 

 amples which I have examined. Typical gemina — that form with 

 sharply defined elytral vittae — is exceptional ; from this there is a grad- 

 ual transition to the more common ;/^/w/(?j-a form with elytra intricately 

 maculate. There is a noticeable variation in the density and rugosity 

 of the abdominal punctuation, but in all specimens, with a single ex- 

 ception, the surface of the basal segments is smooth and shining be- 

 tween the punctures, at least at the middle, becoming more rugulose 

 and subopaque toward the apex. In the exception noted — a speci- 

 men taken by me on Mt. Tamalpais near San Francisco — the en- 

 tire abdomen is alutaceo-rugulose and opaque. I prefer to consider 

 this an extreme variation until further specimens appear. Length, 

 5-6.1 mm., .20-. 25 inch. 



