MOLLUSCA. 763 



cavity in the casts is more slender in this species than in either 

 of the others. Sometimes a second faint, revolving fold is pres- 

 ent upon the columella, situated above the primary one. 



The three specimens which Whitfield has illustrated as the 

 types of his Pyrifusus turritus apparently belongf' to three dif- 

 ferent species of as many different genera. One of the speci- 

 mens, probably the best of the three, preserved in the collection 

 of the Philadelphia Academy of Science, has been shown, upon 

 cleaning out the columellar cavity, to have a distinct columellar 

 fold, and the specimen differs in no essential manner from the 

 type of Odontofusus medians. 



Formation and locality. — Marshalltown clay-marl, near 

 Swedesboro (180) ; Navesink marl, Atlantic Highlands (108), 

 Crosswicks Creek (149, 195). 



Geographic distribution.' — New Jersey, Mississippi. 



Odontofusus typicus Whitfield. 

 Plate XC, Figs. 7-16. 



1892. Odontofusiis typicus Whitf., Pal. N. J., vol. 2 (Monog. 

 U. S. G. S., vol. 18), p. 66, pi. 6, figs. 1-5. 



Description. — "Shell when of full size about 2 inches long in 

 the extreme, so far as yet known ; spire elevated, forming about 

 one-half of the entire length of the shell, which contains about 

 four and one-half to five volutions in the condition of internal 

 cast; volutions angular, rather strongly so in the principal one, 

 forming an angulated periphery which is crossed by 10 or 12 

 prominent, vertical ridges, which generally show as transverse 

 nodes on the periphery and only extend a short distance above or 

 below, apparently never reaching to the suture line ; lower portion 

 of the body volution extended so as to form a rather slender an- 

 terior beak, about equaling in length the vertical diameter of the 

 body volution, as seen from the dorsal side ; aperture moderately 

 large, angular at the middle of the outer Hp and extended below 

 in a narrow canal; columella marked by a single, rather strong, 

 oblique fold, situated near the middle of the aperture proper; 



