MOLLUSCA. 485 



Pornation and locality. — Navesink marl, near Walnford 

 (1481, 148^), Holmdel and Freehold (Whitfield). 

 Geographic distribution. — New Jersey. 



Plicatula mullicaensis n. sp.. 

 Plate LIL, Figs. 3-5. 



Description. — ^Shell obliquely ovate. The upper valve de- 

 presed-convex, marked by radiating costae and concentric lines 

 of jrowth, at the junction of which the radiating costae are pro- 

 dued intoi short spines. 



'he dimensions oif an average specimen are : total length, 30 

 ms. ; width, 22 mm. 



Remarks. — This species is abundant at Mullica Hill and has 

 uaally been identified as P. urticosa. It differs from that 

 secies, however, in its much more regular outline and in its 

 luch finer surface markings. Only the upper valves of the 

 jecies have been observed, but these seem to be more uniform 

 1 their characters than is usual for members of this genus. 

 FormaHon and locality. — Navesink marl, Mullica Hill (169). 

 Geographic distribution. — New Jersey. 



Plicatula woodburyensis n. sp. 



Plate LII, Figs. 8-9. 



Description. — Upper valve subovate in outline, only slightly 

 oblique, moderately convex on the umbo, the remainder of the 

 valve nearly flat. Marked by more or less alternating radiating 

 costse which are nearly obsolete upon the umbonal portion, be- 

 coming regularly stronger towards the margin, those in front 

 and behind the umbo> curving strongly upward, the costae ele- 

 vated at intervals into small, short spines directed at nearly 

 right angles to the surface o-f the shell. Lower valve not known. 



The dimensions of the type specimen are: height, 28.5 mm.; 

 width, 26 mm. 



Formation, and locality. — Woodbury clay, Lorillard (102). 



Geographic distribution. — New Jersey. 



