PTEROSTICHIN.E 379 



fering decisively, of course, in the longer met-episterna. Desidi- 

 osus very closely resembles femoralis, and does not seem to differ 

 materially in strial punctuation as stated by LeConte, but it is 

 nevertheless distinct in its entirely rufous legs, more abbreviated 

 form of the body and more oval elytra. The following is allied to 

 femoralis and desidiosus in strial punctuation, but differs in the 

 form of the prothorax: 



Micromaseus aequicollis n. sp. Body elongate, moderately convex, 

 very shining, the type ferruginous but very immature, probably nearly 

 black in maturity; femora not quite so dark as the tibiae; head four-sev- 

 enths as wide as the prothorax, with large though but slightly prominent 

 eyes and unusually short sulci; antennae half as long as the body, very 

 slender and equally filiform, the basal joint nearly twice as thick as the 

 remainder ; prothorax widest exactly at the middle, parallel, scarcely visibly 

 shorter than wide, the sides very evenly and equally arcuate from apex 

 to base, the basal angles sharp and minutely, feebly prominent; base as 

 wide as the rather deeply sinuate apex; surface wholly impunctate, the 

 fovea not long, rather narrow and not attaining the base, which is finely 

 margined, the margin interrupted medially; median stria extremely fine; 

 elytra three-fourths longer than wide, scarcely a fifth wider than the 

 prothorax; striae rather coarse, not very deep and strongly punctured, 

 more closely than in femoralis; scutellar stria rather long and finer, punc- 

 tured, interrupted basally in the type; intervals only feebly convex. 

 Length (o") 6.0 mm.; width 2.0 mm. Missouri (St. Louis). 



The peculiar form of the prothorax, which is widest at the middle 

 and with perfectly parallel and evenly arcuate sides throughout, 

 will enable one to identify this species at once. The single type 

 specimen is extremely immature. 



I have at present no representative of Pterosticlhis obesulus or 

 splendidulus of LeConte, but, from the published characters, they 

 should apparently each form the type of a peculiar generic group. 



Loxandrus Lee. 



Megalostylus \\ Chd. 



The peculiar neatness of appearance, the highly polished integu- 

 ments, generally with distinct iridescent lustre, and the remarkable 

 fleetness of foot characterizing the species of this genus, might, 

 with some unscientific license, justify us in regarding them as the 

 grayhounds of the Pterostichinse. The species are very numerous 

 and probably number far more than one hundred. They are essen- 

 tially southern, only a few occurring as far to the northward as the 



