634 On Aquatic Carnivorous Coleoptera or Dytrscide. 
there is generally a minute fleck : the ventral segments are sometimes marked with 
yellow. 
The sculpture on the elytra of the female consists sometimes of some very fine 
short impressions extending along the middle of the elytra in the longitudinal 
direction; at other times the impressions are coarse and deep, occupying the 
basal portion of the wing-case from the suture to near the outer margin. 
Very widely distributed in America, from Mexico and the West India Islands to Parana. 
Grovp 3. 
1071. Dytiscus basilaris, Harr., Aeilius basilaris, M.C.—Minor, parum convexus, 
nitidus, subtus vel rufus vel piceus, supra niger, capite anterius et in medio verticis, 
prothorace lateribus fasciaque mediali transversa, elytris lateribus fasciaque sub- 
basali plus minusve integra, antennis pedibusque anterioribus testaceis ; colore 
testaceo ad latera et ad apicem elytroruma lineis et ab irrorationibus nigris disinte- 
erato ; pedibus posterioribus piceis (vel rufis,) tibiis sepius nigricantibus ; epipleuris 
angustis. Long. 10, lat. 5§ m.m. 
Fem., prothorace elytrisque utrinque punctis elongatis, rudis profundis (plus 
minusve numerosis) impressis. 
In the male of this species the large basal palette of the front tarsus is much larger 
than the two next largest, these indeed are but little larger than the adjacent ones, 
while the more outward ones are still smaller; the fringing hairs are better 
developed than in the allies, and are not interrupted at the point of articulation 
with the tibia as they are in all the other species. 
The species is very variable in size and colour, and in the sexual sculpture of the 
female: but I do not find the characters constant in the series before me so that [ 
am unable to see more than one species in the variations: individuals reddish 
beneath seem to occur only in California, and the magnitudes of the palettes in the 
male seems to depart slightly from what exists in individuals from the eastern 
United States; Iam not able from the series before me however to distinguish 
more than one species, few of the individuals being in sufficiently good preservation 
to allow me to form a positive opinion on such points. 
North America, United States and Mexico, Guatemala. 974. 
I. 71.—Genus GiTHIONECTES. 
Coxal lines distinct in their hinder portion, supra-articular border broad; middle 
femora with only short seteze. 
A single species from tropical Africa. 
