AQUATIG COLEOPTERA 
COLLECTED BY M. CAMILLE VAN VOLXEM 
IN BRAZIL 
DAVID SHARP M. B. 
— SÉANCE DU 1‘ SEPTEMBRE 1877 — 
1. Cybister lævigatus (O1) Aubé. M. C. van Volxem has 
found a large number of individuals of this variable species at 
Santa Cruz, 10 to 17 oct. 1872; they are a variety in which the 
female has only some short, deep, linear marks on the elytra about 
the shoulders; the specimens shew a little, but only a little varia- 
tion as to the extent of these marks. 
2. Cybister n. sp. M. C. van Volxem found at Santa Cruz 
five individuals of a Cybister similar in size and form to C. cos- 
talis, but the female has the elytra quite smooth. It is possibly a 
new species, but as [ am at present engaged in revising the 
family, and as the species of Dytiscidæ are very difficult to make 
out, it will be better to leave the point undetermined for a little. 
3. Acilius circumscriptus (Aubé) var. (Thermoneclus sub- 
fasciatus Dej.) Rio de Janeiro, Santa Cruz, 10 to 17-10-72. 
4. Acilius succinctus Aubé. Entre Rios, Santa Cruz, 10 to 
17-10-72. 
5. Acilius margineguttatus Aubé, Santa Cruz 10 to 17- 
10-72. 
6. Acilius incisus Aubé, var. Three individuals from Santa 
Cruz must at present be referred to this species, which according 
to Aubé is an excessively variable one. . 
7. Colymbetes ïrroratus (Brullé) Aubé. Buenos Ayres. 
8. Colymbetes calidus (Fab.) Aubë. Santa Cruz, Rio Janeiro, 
Entre Rios. 
