536 CRETACEOUS PALEONTOLOGY. 



front as the anterior extremity of the shell, incurved and directed 

 fo'Hvard. Post-umbonal slope abrupt, with a shallow sinus ex- 

 tending from the beak toi the posterior margin of the shell, and 

 a low subangular ridge curving from the beak to the postero- 

 cardinal extremity; anterior slope convex from the umbonal 

 ridge forward, the curvature of the surface becoming much 

 more abrupt as it approaches the anterior margin. Surface 

 of the shell marked by several, strong, concentric varices which 

 become more remote away from the Ijeak, and upon very large 

 individuals become obsolete upon the outer portion of the shell; 

 they are produced into broad, lamellar extensions of the shell 

 and do' not continue across the post-umbonal slope. The shell 

 surface is also marked by more or less irregular concentric lines 

 of growth. 



Remarks. — This is one of the long range species in the New 

 Jersey faunas, and is liable to occur at any horizon from the 

 Merchantville to the Tinton. The species does not usually at- 

 tain so large a size in New Jersey as it sometimes does in some of 

 the southern localities, although individuals 30 mm. in height are 

 sometimes met with. The little shell from Haddonfield described 

 by Conrad as V. elevata is only a young individual of V. con- 

 radi, and the same author's Goniosomo iniicbta is an internal cast 

 of the same. The species occurs most abundantly in the Mer- 

 chantville, Marshalltown, and Wenonah formations, being rare 

 in the Woodbury. The only place where the shells themselves 

 have been collected in the State is from the Marshalltown clay- 

 marl near Swedesboro. 



Formation and locality. — Merchhantville clay-marl, near 

 Jamesburg (139, 140, 141), Merchantville (162), Lenola (163) ; 

 Wenonah sand, near Marlboro (130^), near Crawfords Corner 

 (126^); Navesink marl, Atlantic Highlands (108), near Craw- 

 fords Corner (126'^), near Walnford (149), Mullica Hill 

 (169^); Red Bank sand. Red Bank (116), Shrewsbury River 

 (199), near Middletown (112); Tinton beds, Beers Hill cut, 

 south of Keyport (1291^). 



Geographic distribution. — New Jersey, Alabama, Mississippi. 



