AQUATIC COLEOPTERA. 121 
with the base more or less infuscate, it is rather coarsely punctu- 
red, the punctures across the middle being more sparing than at 
the base and in front; there is no impressed stria. Elytra with the 
shoulders prominent, of a dark testaceous or ferruginous colour 
with the series of punctures placed in black, but not conspicuous 
lines, and with still more indistinct black spots; the lines of 
punctures becoming coarser towards the side, and the insterstices 
are only very sparingly punctured; the sides of the epipleuræ 
appear finely serrate. The prosternal process has the sides acutely 
raised. 
The species is very closely allied to Haliplus gravidus Aube, 
but is not quite so broad nor so dark in colour, and not quite so 
coarsely punctured. 
GYRINIDÆ. 
1. Dineutes metallicus Aubé. À large series of specimens 
shews very little variation, except that between the sexes there is 
much difference. 
2. Gyretes morio Aubé. A single individual ©. 
HYDROPHILIDÆ. 
1. Hydrophilus insularis Cast. 
2. Tropisternus corvinus Chev. A single individual appears 
to differ but little from a Mexican species bearing this name in 
collections. 
3. Tropisternus lateralis Fab. (Hydrophilus.) 
Besides the above, there are also in M. Purves’ collection four 
species of Berosus, and a Philhydrus represented by single indivi- 
duals, which I am unable to determine. 
