On Aguatic Carnivorous Coleoptera or Dytiscide. 617 
variabili, antennis pedibusque anterioribus rufis, pedibus posterioribus piceis, crassis, 
tarsorum articulis lobato-productis, unguiculo interno quam externo crassiusculo 
plus duplo longiore. Long. 123, lat. 64 m.m. 
The male has the front and middle tarsi only very slightly incrassate and entirely 
compressed, and furnished beneath with minute palettes, their claws are nearly 
equal and simple. The species varies a good deal in size and in the colouring of 
the upper surface, but very little in other respects. 
America, from Brazil to the United States of North America, (Rio de Janeiro, Amazons, Venezuela, 
Peru, Guatemala, Mexico, Texas). 889. 
943. Dytiscus grapii, Gyll., Colymbetes grapu, M.C_—Ovalis, parum convexus, 
niger, subopacus, antennis palpisque testaceis, pedibus, prothoracis lateribus clytro- 
rumque epipleuris piceis, supra creberrime subtilissimeque reticulatus ; prothorace 
basi utrinque profunde sinuato, angulis posterioribus prolongatis ; prosterno medio 
anterius parum elevato ; tarsis posterioribus articulis extus inferne bene lobatis, 
unguiculo interno quam externo duplo longiore. Long. 11, lat. 5{ m.m. 
The male has the front and middle tarsi a good deal incrassate but quite com- 
pressed, and furnished beneath with four rows of small palettes, the marginal hairs 
are moderately long; on the front feet the basal portion of the tarsus beneath is 
quite bare and shining, and the claws are moderately long and nearly equal and 
simple ; on the middle feet the basal portion of the tarsus beneath is occupied by a 
large patch of dense glandular pubescence, and the claws are thick, the outer one 
especially being much incrassate beneath, and quite distinctly longer than the 
inner one. 
Europe, (Sweden, Finland, Lapland, England, France, Germany ; Constantine, Algeria, teste Bedell). 
890. 
944, Colymbetes sinuatus, Lee., Proc. Ac. Phil. 1866, p. 522.—Ovalis, perum 
convexus, niger, subopacus, antennis palpisque testaceis, prothoracis lateribus 
elytrorumque epipleuris piceis, supra creberrime subtilissimeque reticulatus; pro- 
thorace basi utrinque profunde sinuato, angulis posterioribus prolongatis ; prosterno 
medio anterius parum elevato; tarsis posterioribus articulis extus inferne bene 
lobatis, unguiculo interno quam externo plus duplo longiore. Long. 10, lat. 5 
m.m. 
Extremely closely allied to the preceding, but much smaller. 
North America, (Dacotah, Illinois). 895. 
945. Dytiscus pustulatus, Rossi, Sewtopterus pustulatus, M.C.—Ovalis, convexus, 
nigricans, vix supra subzenescens, limbo piceo, antennis palpisque rufis, pedibus 
