1 6 Bulletin 5 386 



38 Say on Shells, &c. 



The several different appearances exhibited b}^ specimens 

 of the Pentremite may be thus defined — 

 I St. Pelvis abruptly attenuated, nearly horizontal — 



Length from seven tenths to more than half an inch. 

 Kentucky A sterial fossil, Park. Org. Rem. vol. 2, pi. 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 in a 

 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 Echimis 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 b}'' Jameson p. 363, 

 pi. 8. This figure indicates the above first variety. 



Renilla Americana, 



Is very common on the coast of Georgia and E. Florida, 

 cast up by the waves. 



Perna torta. 



This large species of fossil Perna has been discovered at 

 Upper Marlborough, in the state of Maryland, by Mr. J. 

 Gilliams of this cit3^ 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 then! the substance of 

 the shell is in a tolerable state of preservation, not having 



[A. J. S., ist Ser., Vol. II.] 



