462 O. Meyer—Species in the Southern Old-tertiary. 
39. A Corbula in Jackson — from Corbula Bsc Lea in 
d 
having less distinct concentric ribs and a a aller beak. 
The last difference is important en attr to justify a new name 
Corbulu Willistoni,* but otherwise the dotaila are alike 
40. Corbula bicarinata ©. from Jackson differs from °C. Murch- 
isoni Lea in having the concentric ribs somewhat more numerous 
and the umbonial carina less distinct, but this variation is slight. 
41. Corbula densata CO. from Jackson has indeed, as Conrad 
says, a shorter form and a more rounded base than C. Alabami- 
ensis Lea, but there are quite a number of specimens ie _— the 
appearance in Claiborne, which I tried in vain to separate 
specifically from the elongated forms. So the ‘antes specimens 
oe only a variety 
om Vicksburg and Claiborne I have a Dentalium, which 
agrees with my specimens of Dent. microstria Heilpr.t from 
Wood’s Bluff. One of the Claiborne specimens has the posterior 
aperture se showing an emargination and opposite to it a 
fissure. Although Heilprin in his description says “posterior 
aperture entire, there being no fissure,” I have little doubt that it 
is the same species and that he described an incomplete aperture. 
The species is too rare and occurs too — to enable me 
to give a sure representation of its 
_ 44, A small, smooth, even por a ie a Dentalium, occur- 
ring in Vicksburg and Jac — is rsp PHS from all other 
mpressurn 
In Claiborne occurs a Dentalium, which has not been de- 
ented, though fragments of it are not rare. The shell is solid, 
smooth without any ribs; section circular. The posterior apet 
ture is formed very characteristically, The margin is notched 
ae the notches are opposite, deep and almost of the same es 
s the remaining two opposite prominences of the margin. ta 
within, a little tube rises. ‘This species may be called entation 
Leai in honor of I. Lea, whose “Contributions to Geology” I 
Jackson occurs a species, fragments of which cannot be distin- 
guished from the Gisiborns form. The posterior aperture how- 
although showing also the little tube, has only one of the 
tches, which moreover is less deep. It may be called Dentalium 
ey As the other notch is at least indicated by a slight 
emargination, the species are to be related to each other. ; 
46. In Vicksburg and Jackson occur quite a number ‘of species 
of Cadulus. One of them in Jackson, Cadulus J 
n. Sp., is the largest one. The inflation is near the anterlo 
* In honor of m 
ee ee foe ee 
Jahresb. d. Senckenb. Naturf. Geselisch., Frankfurt a. M., 1882-3, p. 258. 
