STENUS. 6ol 
white pubescence on the base of each segment of the abdomen is very distinct. ‘The 
male characters are, I think, similar in the two species. 
B. Abdomen immarginatum. 
As this section includes the greater number of our species, and as it is here that 
we meet with the larger part of the peculiar forms of our region I have thought it 
advisable to divide it into four groups. 
§1. Thorax short and broad; head without polished elevation ; tarsi broad, with the 
third joint more or less lobed or produced on one side ; size considerable. 
The species of this group have North-American and European allies, e. g. 8. recon- 
ditus, Casey, and S. tarsalis, Ljungh. 
26. Stenus consimilis. (Tab. XVII. fig. 9.) 
Niger, subopacus, breviter albido-pubescens ; antennis palpisque flavis, illis articulo basali nigro ; dense, fortiter 
eequaliterque punctatus ; abdomine a basi ad apicem angustato ; tarsis fusco-albidis. 
Long. 6 millim. 
Hab. Mexico (Trugui, Sallé), Las Vigas (Flohr), Jalapa, Cordova (Hége), Popocate- 
petl 12,500 feet (Zruqut). 
Antenne and palpi only moderately long, yellow, each slightly sordid towards the 
apex, the basal joint of the former black. Head nearly as broad as the elytra, evenly 
and closely punctured; not excavate, rather indistinctly bisulcate, the middle portion 
broad, wider than the juxta-ocular interval. Thorax rather longer than its greatest 
width, which is a little in front of the middle, a good deal curved at the sides, much 
narrower than the elytra, densely and evenly punctured like the head. Elytra slightly 
longer than the thorax; the punctuation dense, almost the same as that of the thorax, 
and not at all rugose. Hind body elongate; the punctuation not differing greatly from 
that of the elytra, but not quite so coarse, and at the apex not so close or coarse. 
Legs black; tarsi pallid but more or less infuscate, the lobes very distinct, short 
and broad. Male with a short broad notch on the hind margin of the last ventral 
segment. 
This insect has a more conical hind body than the European S. ¢arsalis, and at first 
sight reminds one rather of S. pubescens, Sturm, a species belonging to a different 
section of the genus. It is probably common, as it has been received from several 
sources though in small numbers; Herr Hoge procured a small series at Jalapa. 
27. Stenus leucopus. 
Niger, subopacus, breviter parciusque albido-pubescens ; antennis palpisque flavis ; fortiter punctatus, abdomine 
subtilius punctato; tarsis fusco-albidis. 
Long. 54-6 millim. 
4002 
