48 AMERICAN JOURNAL 



much smaller size than the Mississippi specimen, and a great 

 deal shorter in proportion. 



SCAMBULA, Conrad. 

 Hinge with two approximate teeth in the right valve, the pos- 

 terior one direct and ending at the apex ; a long anterior double 

 tooth parallel with the straight cardinal line ; anterior muscular 

 impression small, rounded. 



S. PERPLANA. — PI. 9, figs. 7, 8. 



Description. — Elongated, triangular, flat ; disk uneven, faintly 

 striated concentricallj ; a few prominent, fine concentric ribs on 

 the umbo; anterior margin obliquely truncated; posterior dorsal 

 margin concave ; apex acute, perfectly erect. 



Locality. — Haddonfield, N. J. 



This singular shell is perfectly flat on the disk, so that the 

 space for the animal was exceedingly small. The ventral mar- 

 gin is carinated anteriorly, and the inner surface of the valves is 

 granulated. 



GOULDIA. 

 Go DECEMNARIA. — PI. 9, fig. 4. 



Description. — Minute, inequilateral, convex, with about 12 

 concentric prominent ribs. 



Locality. — Haddonfield, N. J. 



G. DECLIVIS. — PI. 9, fig. 5. 



Description. — Minute, triangular, compressed, equilateral, 

 summit acute ; posterior extremity angular ; disk with numerous 

 very regular, close concentric lines. 



Locality. — Haddonfield, N. J. 



VBTOCARDIA, Conrad. 



Trapezoidal or subtriangular, costate ; hinge character— one 

 thick pyramidal tooth under the apex of the right valve, either 

 direct or pointing obliquely backwards, a pit on each side ; left 

 valve — one long very oblique tooth, directed backwards, and a 

 pit anterior to it. 



A small species of this genus in the Ripley Cretaceous, near 

 Haddonfield, New Jersey, has enabled me to obtain a perfect 

 hinge of both valves. The valves in this genus are sculptured 

 with radiating or concentric ribs, and none have been found as 

 much as one inch in length. The genus is known only in Creta- 

 ceous strata, and is easily recognized by external form and 

 sculpture. 



V. CRENALiRATA, Conrad, [Astarte), Jour. A. N. S. 2d series, 

 vol. iv, pi. 46, fig. 22. 

 V. corhicula ? Conrad. 



