140 Scientific Intelligence. 
Trypanostoma having an expanded outer lip, and an auger-shaped 4 
aperture, | 
Goniobasis having usually a sub-rhomboidal aperture, sub-angular at 
base and without a channel. 
Am~nicola having a round mouth and no callus, Pe 
The number of new species of Unionide which Mr. Lea has described, 
since he commenced the study of this family in 1827, already amountsto 
over 550, nearly all of which are indigenous. Full descriptions, accom- — 
ven of eac 
grea h 
“be required ; and when so, it is important that they should be based, a8 
i he animals, 
of form in the two sexes, a fact unappreciated by European 
had been observ 4s é 
_ -asBieionat in grsttly indcblsc:to. MeLap, fot Isla untiving labore tell 
so many years in this department of Natural History. naa ae 
. 
