152 PALEONTOLOGY OF NEW JEESEY. 



The more transverse form of this shell at once distinguishes it from 

 V. Conradi Morton, as well as from most of the other species found in New 



Jersey. 



Locality, — The only specimen of this species which I have seen from 

 New Jersey is from the Lower Green Marls at Holmdel. 



Genus SPHiERIOLA Stoliczka. 



Sphaeriola umbonata. 

 Plato XIX, Figs. 17 and 18. 



Shell moderately large and very ventricose, with very full, prominent 

 beaks and umbones, which are situated considerably anterior to the middle 

 of the length of the shell. Anterior end of the shell more broadly rounded 

 than the posterior, and the basal line very slightly flattened in the middle. 

 Surface of the cast marked by strong concentric lines, and by a few dis- 

 tant undulations of the surface. Ligament strong and prominent. Further 

 hinge characters unknown. 



Only a single very imperfect cast of this species has been obtained, 

 the condition of preservation of which is such as to render a more complete 

 description of its character impossible. It differs from any of the species 

 from the upper Missouri region in being more inequilateral, and in the in- 

 flated character of the beaks, which are remarkably strong. The speci- 

 men was observed among the collections of the Academy of Natural Sci- 

 ences at Philadelphia, marked Area antrosa. As it is the only individual 

 of the genus yet recognized on the Atlantic border, I have concluded to 

 name it, for the purpose of calling attention to it, notwithstanding its very 

 imperfect condition. 



Formation and locality. — The specimen is marked simply ^^Cret., N. J.,'^ 

 without clue to its definite locality, like so many of the specimens formerly 

 used, and probably collected or deposited in the collection by Messrs. Con- 

 rad and Gabb; through which error the great interest of the specimens is 

 entirely lost to science and their principal uses destroyed. The specimen 

 is a cast in coarse greensand, coated with a blackish deposit of decayed 

 vegetable matter, and I infer it may have come from the Lower Beds of the 

 Cretaceous. 



