AMERICAN COLEOPTERA. 303 



A. exisiium Mels. — Resembles a diminutive form of the preceding species 

 and is known only by its small size,sutural stria more deeply impressed, lateral 

 margin of elytra slightly angulate, body less perfectly contractile. Length 

 extended .08 — .10 inch; 2—2.5 mm. 



Varieties occur in this species in which some have the elytra abso- 

 lutely smooth, others punctulate, they are not however distinct. 

 Sexual characters as in oniscoides. 

 Occurs with the preceding, and in Colorado. 



A. dentigeruin n. sp. — Smaller than exiguum and perfectly contractile as 

 in oniscoides. Antennre with third joint evidently shorter than the second. 

 Surface smooth, shining and impunctate, sutural stria entirely wanting. Body 

 beneath as in oniscoides. Length .06 — .07 inch; 1.5 — 1.75 mm. 



Male. — Anterior tarsi slightly dilated. Posterior femur rather slender with 

 a triangular tooth near the outer condyle. Tarsi 5 — 5 — 4. 



Female. — Tarsi slender, femora simple. Tarsi 5 — 4—4. 

 Two specimens, Stone Creek, Lee Co., Virginia, (Schwarz). 



A. calirornicum n.sp. — Closely resembling eri^rwitw, similarly contractile. 

 Head and thorax microscopically alutaceous, elytra sparsely but very distinctly 

 punctulate, sutural stria moderately deeply impressed and extending from the 

 apex beyond the middle. Length .08 — .10 inch; 2 — 2.5 mm. 



Sexual characters as in exiguum. 



When viewed laterally the margin of the elytra is more distinctly 

 angulate than in exiguum but not more so than in dentigerum. 



Occurs in California, Nevada and Washington Territory. 



A. revolvens Lee. — Broadly oval, piceous, shining, semi-contractile. Head 

 sparsely finely punctulate. Thorax less than twice as wide as long, narrov/ed 

 in front, apex deeply emarginate, base broadly arcuate, sides not continuously 

 arcuate with the base, hind angles distinct but rounded, surface sparsely very 

 finely punctulate. Elytra oval longer than wide, base at sides oblique, humeri 

 rounded, sutural stria rather deeplj' impressed from middle to apex, surface 

 substriate, sparsely punctulate, the punctures coarser and denser than on the 

 thorax. Mesosternum oblique, finely carinate in front. Metasternum without 

 oblique line, surface alutaceous sparsely punctate. Abdomen sparsely punc- 

 tate. Length extended .14 inch; 3.5 mm. 



Sexual characters as in oniscoides. 



This species from the structure of the base of the thorax is far less 

 contractile than the preceding species. In some specimens, particu- 

 larly the males, there is a tendency in the seventh joint of the antennae 

 to become larger than the eighth, showing an approach toward Liodes 

 which is also indicated by the less contractile power. 



Occurs from Canada to Vancouver. 



A. sexstriaf um n. sp. — Oblong-oval, moderately convex, scarcely at all 

 contractile, piceous, thorax orange-red, shining. Head sparsely finely punctu- 

 late. Thorax more than twice as wide as long, much narrowed in front, sides 

 arcuate, apex deeply emarginate, base feebly arcuate, hind angles subrect- 



