38 Say on Shells, &c. 
The several different appearances exhibited by specimens 
of the Pentremite may be thus defined— . 
ist. Pelvis abrubtly attenuated, nearly horizontal— 
Length from seven tenths to’ more than half an ineh. 
Kentucky Asterial fossil, Park. Org. Rem. vol. 2, pl. 13. 
_ This is the most common. 
2d. Body oblong ; pelvis gradually attenuated ; transverse 
elevated lines of the ambulacra, grooved— 
Length from three fourths to one inch and one fourth. 
3d. Body subglobular ; pelvis hardly more attenuated than 
the superior portion— 
Length about one inch— 
Less common than the preceding ones. 
In Peale’s Museum a large specimen of the latter is pre- 
served, of which the sutures, have each a parallel impressed 
line on each side; this specimen was brought from England 
by Mr. Reubens Peale, he was informed that it was found 
in the vicinity of Bath, but the fact is very equivocal. 
A specimen of the second variety is in the collection of 
Mr. B. Say ; it was presented to him several years ago un- 
der the name of petrified althea bud, and was dug up ina 
garden in the borough of Reading, Pennsylvania. 
Mr. Z. Collins informed me that this fossil has been 
noticed and figured, by Dr. S. L. Mitchell, of New-York, 
as an Echinus “of the family (genus) Galerite, and also as an 
asterite. See his geological observations in the New-York 
edition of Cuvier’s theory as translated by Jameson p. 363, 
pl. 8. This figure mdicates the above first variety. 
Renilla Americana, 
Is very common on the coast of Georgia and E. Florida, 
cast a by the waves. 
Perna torte, 
This large species of fossil Perna has been discovered at 
Upper Marlborough, in the state of Maryland, by Mr. J. 
Gilliams of this city. The hinge portion is very entire, but 
the anterior part, is more or less broken off, as is the case 
with those found in Europe and like them the substance of 
the shell is in a tolerable state of preservation, not having 
