On Aquatie Carnworous Coleoptera or Dytiscide. 601 
I. 59.—Genus COPTOTOMUS. 
- Palpi with their terminal joints a little incrassate, and rather deeply notched at 
the extremity ; prosternum thickened alone the middle. 
The three species* are North American. 
910. Coptotomus obscurus, n. sp.—Ovalis, convexus, minus elongatus, nitidus, 
testaceus, subtus rafo-testaceus, vertice, prothorace anterius et posterius in medio 
elytrisque vittis irregularibus plus minusve coalescentibus nigris; corpore supra 
crebre subtiliter punctato ; prosterno in medio crasso, anterius perpendiculari ; 
coxis posterioribus magnis. Long. 7, lat. $2 m.m. 
The male has the basal joints of the front and middle tarsi a little incrassate, and 
furnished beneath with moderately long hairs, bearing small palettes ; the claws on 
the front feet are slender and moderately long, the front one having beneath in the 
middle a very minute thickening, while the hinder has the basal portion more 
distinctly emarginate ; there is a slight difference in the sculpture of the elytra in 
the two sexes ; in the female the punctuation on the basal portion of the elytra is 
more distinct and regular than in the male, the punctures being slightly elongated 
so as to form excessively short striz. 
The species is excessively similar to the two following, but is smaller and darker 
in colour, especially beneath, and has the hind coxee more free from sculpture, and 
their front border nearer to the middle coyal cavities; the sexual distinctions are 
also less conspicuous. 
North America, (Texas, Florida’. 910. 
911. Dytiscus interrogatus, Fab., Coptotomus interrogatus, M.C.—Ovalis, con- 
vexus, sat clongatus, nitidus, testaceus, vertice, thorace anterius et posterius in 
medio, elytrisque vittis irregularibus plus minusve coalescentibus nigris ; corpore 
supra crebre subtiliter punctato ; prosterno in medio crasso, anterius perpendiculari, 
coxis posterioribus magnis, subrugosulis. Long. 8, lat. 4 m.m. 
The male has the basal joints of the front and middle tarsi a little incrassate, and 
furnished beneath with long hairs, bearing small palettes, the claws of the front 
feet are rather long, and have their basal portion shehtly emarginate beneath, this 
is more distinct on the posterior than on the anterior one. In the female the basal 
*The two following species unknown to me are probably closely allied to, if distinct from, one or 
other of those described in the text. Coptotomus difficilis, Lec., (No. 1272 huj. op.)? No. 911 var. 
North Ainerica.—Coptotomus serripalpus, Say, (No. 1273); Mexico. 
