48 ADEPHAGA. 
is very widely distributed, and possesses also three or four North-American species, but 
is quite absent from South America. 
1. Cybister fimbriolatus. (Tab. I. fig. 14.) 
Dytiscus fimbriolatus, Say, Trans. Am. Phil. Soc. ii. p. 91; Sharp, Trans. Roy. Dubl. Soc. n. s. ii. 
p. 715. 
Cybister dissimilis, Aubé, Spec. Gén. vi. p. 69. 
Hab. Nortu America, from Pennsylvania southwards.—Mexico, Guanajuato (Duges, 
coll. Sallé), Puebla, Toluca (Sallé), Vera Cruz, Oaxaca (Hoge). 
The species is apparently variable in Mexico. Only one of the individuals before me 
(the unique female from Guanajuato) resembles the North-American individuals; the 
other specimens are mostly referable to a well-marked variety of short form, with the 
yellow cincture broad, and with the breast green: of this variety 1 have not seen the 
female. A third form is represented by a single female from Vera Cruz ; it is of elongate 
form, with very broad cincture, and apparently approximates greatly to the Californian 
C. ellipticus, Lec. 
2. Cybister flavocinctus. 
Cybister flavocinctus, Aubé, Spec. Gén. vi. p. 78*; Sharp, Trans. Roy. Dubl. Soc. n.s. ii. p. 716. 
Hab. Nortu America, Texas. —Mexico, Corafalce! (Madame Sallé). 
Fam. GYRINIDZ. 
This small family of Coleoptera is one of the most isolated of all those included 
in the order. All the species have the habit of swimming with extreme rapidity 
in complex curves on the surfaces of various waters, the Orectochilini being frequently 
found in pools in rapid mountain-streams, while the Dineutes group of genera select 
calmer waters for their habitat. 
ENHYDRUS. 
Enhydrus, Cast. Etud. Ent. p. 110; Aubé, Spec. Gén. vi. p. 651. 
This is a genus with several species peculiar to South America; for although at 
present only two are recorded thence, yet certain species (Gyrinus buqueti, Aubé, e. g.) 
hitherto placed in Gyrinus belong rather to Enhydrus. The only other province from 
which species are recorded is New Holland; but Chili possesses two or three species 
allied to the Australian forms. 
1. Enhydrus atratus. 
Enhydrus atratus, Regt. Ann. Soc. Ent. Fr. (5) vi., Bull. p. ecxv. 
Hab. PANAMA. 
