8o Memoirs on the Coleoptera 



analogous to the more posterior impression observable in some 

 species of Anchomemis, such as cincticollis, reflexus and excavatus, 

 and has probably a similar origin; it is impossible to surmise the 

 etiology or significance of it. 



Micragonum n. gen. 



There are no peculiar or exceptional structural characters to 

 distinguish a considerable series of small and more or less ventricose 

 species, allied to nutans and ferreum, as a genus different from 

 Agonum, but in general habitus, which after all is the most important 

 criterion, they differ so radically as to admit of no confusion; most 

 of them, in fact, recall the genus Europhilus more than they do 

 any form of typical Agonum. There are three subgeneric groups 

 as follows: 



Elytra with three dorsal punctures; sides of the prothorax and elytra 

 very finely reflexed; elytra relatively broader, with coarse and 

 basally sulciform striae and very coarse punctures; integuments 

 rather thick; antennae normal in coloration Group I (ferreum) 



Elytra with three to five or six fine dorsal punctures; body more elongate, 

 with the integument thinner, the striae never sulciform 2 



2 — -Sides of the prothorax and elytra very finely reflexed; thoracic 

 fovese usually punctate; elytra shining in both sexes, the striae 

 impunctate to very moderately although distinctly punctate, the 

 dorsal punctures five as a rule; antennae uniform in coloration 

 except at base Group II (nutans) 



Sides of the prothorax and elytra sharply and distinctly reflexed and 

 diaphanously pale, the elytra opaculate, especially in the female; 

 dorsal punctures five in number, the striae not evidently punctu- 

 late; thoracic foveae smooth, impunctate; antennae with the last 

 four joints very abruptly whitish in color.. .Group III (picticorne) 



There can be but little question that the three type forms above 

 noted require treatment as separate subgeneric groups, by whatever 

 name or other term we may distinguish them. They inhabit the 

 Atlantic regions of the continent exclusively, and no Sonoran or 

 Pacific coast species has apparently yet been discovered. 



Group I — ferreum 



Subgenus Stereagonum nov. 



Three rather closely allied species of small size and notably 

 abbreviated form alone constitute this subgenus at present. The 



