the gradations are such that it is difficult to draw 
The Pachydomus gigas of M’Coy, falls into the 
, being between Cleobis and Maonia as these genera were 
a generic character, among these species. The Pachydomus globosus 
of Morris and M’Coy, appears to be a different species Kies the P. glo- 
bosus of Sowerby, whose figure in Mitchell’s Australia, (PI. 1, p. 14, vol. i,) 
represents a specie s with very thick valves, and from Harper's Hill, 
instead of Illawarra. Morris’s species is believed to be Cleobis grandis 
of the writer. 
The species referred in our former bitiale to Modiolopsis, (Hall,) 
appear to have two muscular impressions, and for the most part more 
erat aeons with the Cypricardiae. 
A gan of Sound in Lepidoptera; by 8.8. Hatpeman.—The 
rby, (Fauna Bor. -Am., p . 305,) or an allied species, 
alludes to an opinion of Dr. Fitch upon the same sub- 
fust be an error attributable to the fact, that the writer 
wk on the renee of Mexico; by S. 8. Hatpeman, (in a 
ors.)—I have recently received a small collec- 
Hts from auavawe (Chihuahua) and Santa Fé ; they are 
‘condition, but a cursory examination seems to give the fol- 
: ‘ies, well known in this part of the United iB ‘Siow 
atum, Acrydium ornatum, Syrtis erosa, Carabus se , Rha- 
calls $ also so Aphodius strigatus, which occurs as far-north as Lake Su- 
pede has been sent to me from Jalapa. 
IV. Asrronomy. 
ed in sauce the whole foi Ak “of ‘Deets 
Neptune, and it was intimated that we might find it p 
to our assistance sities planet hitherto unseen. d 
from Professor Peirce the results of his recent compuitons, ‘or ire 
which it will be seen that his labors have been crown ntire 
Success. The annexed table will wee that, assuming the m 
tue to be 3,5 w ; whats Prof. Peirce from Mr. Bond's 
