154 PALEONTOLOGY OF NEW JERSEY. 



reason, so far as I can judge from the description and figure given by Mr. 

 Gabb, to suppose his Venus Bipleyana, Jour. Am. Sci. Phil., new series, Vol. 

 IV, p. 393, PI. LXVIII, Fig. 22, is distinct from this one. The form is said to 

 be proportionally shorter and more pointed posteriorly and the surface ribs 

 €oarser and less regular. Among the specimens from Holmdel and Marl- 

 borough examples may be selected which will more than cover all these 

 differences. 



In regard to the generic affinities of the shell, I can see no reason for 

 separating these Cretaceous forms from those found in the Eocene; in 

 fact, I think those of the New Jersey Eocene are, most likely, specifically 

 identical. Certainly I should not think of classing them under a different 

 genus simply because they were found in a different geological formation, 

 and that only, as do some authors, for I cannot believe in limiting zoolog- 

 ical groups by geological formations. 



Formation and locality. — As casts only in the Lower Green Marls at Free- 

 hold, New Jersey, and as small shells from the nodules in the Lower Marls 

 at Marlborough and Holmdel, New Jersey. Mr. Gabb cites it from the 

 Delaware and Chesapeake Canal and New Jersey. 



Genus APHRODINA Conrad. 1868. 



(Am. Jour. Conch., Vol. IV, p. 246.) 



Aphrodina Tippana. 



Plate XXII, Figs. 6 and 7. 



Meretrix Tippa7ia Conrad. Jour. A. ]^. Sci. Phil., new series, Vol. Ill, p. 326, PI. XXXIY, 



Fig. 18. Gabb, Synopsis, p. 142. 

 Diane Tippana (Con.) Meek. Check-list, p. 13. 

 Aplirodina Tippana Conrad. Am. Jour. Conch., Yol. IV, p. 246, PI. XYIII, Fig. 5. 



Meek, Geol. Surv. X. J., 1868, p. 727. 



Shell of moderate size, transversely ovate or subtriaiigular in outline, 

 with moderately convex valves and prominent subtnmid beaks, which are 

 nearly subcentrally situated and slightly directed forward. Anterior end 

 of the valves broadly rounded and the posterior end more pointed; the 

 greatest length of each situated rather below the middle of the height. 

 Base broadly curved and the postero-cardinal margin rapidly sloping, with 



