On Aquatic Carniworous Coleoptera or Dytiscide. 627 
only by the male tarsi, but by the small development of the vermiculate sculpture 
of the prothorax, and by the wider spaces separating the transverse striz of the 
elytra. 
North America, (Western portion ; Cala. sec, Crotch). 912. 
966. Colymbetes exaratus, Lec., Cymatopterus exaratus, M.C_—Ovalis, elongatus, 
convexus, subtus niger, coxarum posticarum processubus rufescentibus, supra capite 
nigro, anterius testaceo, medio rufo-bimaculato, thorace testaceo, vitta discoidali 
nigra, elytris fuscis, margine laterali testaceo; pedibus testaceis, femoribus medio 
fuscis, prothorace eequaliter conspicue veriniculato, elytris strigis transversis pro- 
fundis remotis. Long. 17, lat. 84 m.m. 
The male has the elytra moderately shining, and the transverse striz of about 
one depth throughout ; while in the female the elytra are very dull with a large 
apical portion shining, the transverse furrows on the dull portion are deeper and 
coarser than on the shining portion, so that the spaces between them are less. 
The male tarsi seem to be almost the same as in the preceding species. The species 
is very similar to Dytiscus striatus (No. 972), but the male may be readily distin- 
guished by the basal band of glandular pubescence on its tarsi, and the female by 
its sculpture, the furrows being finer, and the apical shining portion more clearly 
differentiated from the dull part. 
Western North America, (Nebraska, Kansas, Oregon, Dacotah, Hudson’s Bay, sec. Crotch). 913. 
967. Colymbetes groenlandicus, Aubé, Spec. p. 233.—Ovalis, angustulus, parum 
convexus, nitidus, subtus niger, supra capite anterius rufo, posterius nigro rufo- 
bimaculato, prothorace testaceo medio plaga nigro-fusca, elytris fuscis lateribus tes- 
taceis, pedibus rufis, femoribus medio infuscatis; prothorace parum vermiculato, 
elytris sat profunde transversim strigosis, strigis parum approximatis. Long. 143, 
lat. 7 m.m. 
The male has the prothorax almost smooth, while in the female it bears fine 
vermiculate scratches: the sculpture of the elytra is almost similar in the two 
sexes. 
Greenland. 914. 
968. Colymbetes sculptilis, Harr., Cymatopterus sculptilis, M.C.—Elongato-ovalis, 
angustulus, sat convexus, subtus niger, supra capite anterius rufo, posterius nigro, 
rufo-bimaculato, prothorace testaceo, medio plaga nigra, elytris fuscis, lateribus 
testaceis, pedibus rufis femoribus medio leviter infuscatis; prothorace crebrius, 
gqualiter, undulatim reticulato, lateribus versus angulos posteriores parum rotun- 
datis ; elytris profunde transversim strigosis, strigis approximatis. Long. 16, lat. 
8 m.m. 
TRANS. ROY, DUB. SOC., N.S., VOL. I. 4M 
