On Aquatic Carnivorous Coleoptera or Dytiscide. 589 
decem ante apicem abbreviatis, alternis brevioribus et ad basin plus minusve 
abbreviatis et disintegratis, striaque marginali brevissima. Long. 6, lat. 34 m.m. 
I have not seen the male of this species ; the female has the thorax densely covered 
with elongate scratches, which however are absent from the disc: there are also a 
few very fine scratches on the back of the head; near the outside of the elytron, 
about the middle, there is an elongate area covered rather densely with very fine 
scratches. 
The strize on the wing-cases in this species are rather fine, and the inner one is 
nearly as near to the suture as it is to the second stria; they are more or less 
abbreviated and broken up at the base, especially the second and fourth, while the 
third, fifth, seventh, ninth and tenth, reach very nearly to the base; none of the 
strize extend to near the apex, but leave nearly one-sixth of the length free, and the 
alternate ones are considerably shorter than this ; the submarginal stria is extremely 
short and fine, and may easily be overlooked. 
Central America, (S. Geronimo, Guatemala, Champion). 1160. 
878. Copelatus impressicollis, n. sp—Oblongo-ovalis, angustulus, parum con- 
vexus, fusco-niger, capite thoraceque sordide testaceis, supra fuscis, hoc lateribus, 
elytris basi, antennis pedibusque testaceis; elytris striis decem sat profundis, ad 
apicem paulo abbreviatis, (alternis brevioribus), aliaque marginali valde abbreviata. 
Long. 53, lat. 23 m.m. 
The male has the front and middle tarsi much dilated, and the front tibiz are 
simple: the female has on the thorax very numerous short, isolated scratches, which 
however do not extend to the disc. 
The species a good deal resembles Copelatus glyphicus, but is darker in colour, 
and the striee of the elytra are less prolonged both at base and apex, and the sexual 
characters are different. 
The distance of the first strix from the suture is nearly twice as great as that, 
between it and the second stria ; at the base the strie are rather irregular, the two 
internal and the ninth being there distinctly abbreviate. The submarginal stria 
is very short, and placed behind the middle. 
Central America. (Guatemala City and 8. Geronimo, Champion). 1161. 
879. Colymbetes glyphicus, Say, Copelatus glyphicus, M.C.—Oblongo-ovalis, 
angustulus, subdepressus, fusco-rufus, vel castaneus, antennis pedibusque rufis ; 
prothorace fere levigato, tantum parcissime punctulato, sine strigulis; elytris striis 
decem plus minusve profundis ad apicem fere prolongatis, aliaque marginali anterius 
abbreviata. Long. 5, lat. 23 m.m. 
The male has the front and middle tarsi only slightly dilated ; the front tibize are 
4G 2 
