1903.] NATURAL SCIENCES OF PHILADELPHIA. 267 



various points in its'extent, smooth but dull in luster, devoid of any 

 trace of elevated ribs or threads except toward the smaller end, where 

 some 12 to 16 faintly raised subequal hnes become visible. The pos- 

 terior notch is very feeble and broadly angulate, much feebler than 

 in either of the preceding species. A moderately large example meas- 

 ures 40 mm. in length by 4 mm. in diameter, but the latter dimension 

 occasionally attains 4.5 mm., which would represent a rather large 

 individual. 

 Dentalium zephyrinum ". sp. 



The commonest species at Red Bluff, closely resembUng the preceding 

 in general size, form and slight irregularity of growth, but the longi- 

 tudinal threads are distinct throughout the length and of a different 

 form, being wider and flat, equal, about 16 in number, very strong 

 posteriorly, becoming finer and feebler anteriorly where one or two 

 feebler intermediate threads become visible. The posterior notch is 

 well marked, not broadly angulate but generally rather deeper than 

 wide. The length of the largest individual before me is 41 mm., with 

 a maximum diameter of 4.2 mm. 

 Dentalium polygonum n. sp. 



This species also, from Red Bluff, is still more slender, and 

 is peculiar in being a perfect heptagon in cross-section near the 

 smaller end, the angles of the polygon being minutely elevated, form- 

 ing fine but conspicuous longitudinal threads, which remain distinct 

 to the larger end; the intervals soon acquire two to four finer threads 

 which never become as conspicuous as the primary ribs. The notch 

 is not present on the truncated apex of the only specimen before me. 

 Length 33 mm., width 3.2 mm. 



GASTROPODA. 



The Fusus jnississipicnsis of Conrad is a Latirus allied to jyrotractus, 

 having the columellar Jolds evident though rather feeble. It differs 

 in the entirely rounded outline of the whorls, there being no wide double 

 band or collar below the suture as in that species. It is moderately 

 abundant in the upper marls. 



Fusus vicksburgensis is very rare and alsf) occurs solely in the upper 

 marls. My specimens are all fragmentary, partially decorticated and 

 decomposed. Its broad flat lyra easily distinguish it and the nucleus 

 and nepionic whorls are also peculiar. 



The Vicksburg type of Clavella differs from that of the Eocene 

 horizons in having a small conoidal nucleus. They are probably 

 generically different. As far as I have been able to discover there are 



