134 PALEONTOLOGY OF NEW JERSEY. 



Uferum H. C. Lea, if" not identical. The sutures are, liowever, nuicli more 

 distinct, an inconstant feature, but the only difference easily seen. 



Locality: The specimen is from Mr. Ayers's marl pits, near Shiloh, N. J., 

 and is the propei-ty of Miss Ella Tyndall, of Philadelphia, from whom it 

 was borrowed through Prof Heilprin. 



Family TROCHID.^, 

 Genus LEIOTROCHUS Conrad. 

 Proceedings Acad. Nat. Sci. Phila., 1862, p. 569. 



" Polished, entire, without umbilicus; base of columella with two den- 

 ticles." 



The above is Mr. Conrad's desciiption of this genus given as cited 

 above, and is the only reference or description I can find. He classes four 

 species under it in the list in which the above description is embodied, 

 namely: Monilea distans Conrad, Trochus eborens Wagner, Turbo caperatus 

 Com-ad, and Monodonta kiawahensis Tuomey and Holmes. Of the four 

 there is not one which agrees entirely with the characters embraced in the 

 diagnosis, as Trochus eboreus Wag. has but one denticle on the columella, 

 but otherwise agrees; Monodonta kiawahensis T. and H. has a large umbil- 

 icus, and agrees very well otherwise with the genus Monilea ; Monilea distans 

 Conrad, according to his own description of the species, has the "umbilicus 

 narrow, profound;" while Turbo caperatus Conrad, in his own language, has 

 the "columella slightly swelling near the center," so it would not show the 

 two denticles required by the generic diagnosis. The species T. eboreus 

 Wagner is the species which approaches the nearest and would require that 

 the description should be emended so as to read columella obsoletely denticulate, 

 if it is to be used at all — for which there seems but little reason. The 

 diagnosis would then read: Polished, entire, without umbilicus; columella 

 obsoletely denticulate. 



