294 CRETACEOUS PAI.EONTOLOGY. 



1893. Cassidulus cequoreus Clark, Johns Hopkins Univ. Circ, 



vol. 12, No. 103, p. 52. 

 1893. Cassidulus cequoreus Qark, Bull. U. S. G. S., No. 97, 



p. 68, pi. 29, figs. I a-i. 

 1905. Cassidulus cequoreus Johns., Proc. Acad. Nat. Sci. Phil. 



I9Q5, P- 7- 



Description. — Test subpentagonal, depressed conical, longer 

 than wide. Ambulacral areas narrow, poriferous zones unigem- 

 inal; petaloid on the upper part of the dorsal surface at a point 

 varying in the different areas from one-quarter to one-third of 

 the distance fro^m the margin to the apical system, the zones are 

 contracted and continue as narrow bands over the margin and 

 to the vicinity of the peristome, where they broaden again per- 

 ceptibly, becoming finally much contracted at the margins of the 

 oral opening. The pores are distinct in the petaloidal portion 

 and in the broadened area near the peristome, but in the inter- 

 mediate contracted portion they are small and indistinct. Inter- 

 ambulacral areas broad, covered by small perforated tubercles 

 with sunken areolas. The apex forward of the center, the apical 

 system, composed of four perforated genital and five small radial 

 plates; the fifth genital obsolete. The peristome pentagonal, 

 surrounded by a well-developed floscelle; the oral lobes very 

 prominent and the ambulacral furrows much contracted. The 

 anal opening is situated in a short sulcus on the upper surface. 



The dimensions of a complete individual are: length, 31.25 

 mm.; width, 28.12 mm.; height, 15.6 mm. 



Remarks. — This species may be separated from C. Uorealis 

 (Morton) by its more depressed and elongate form. Erom C. 

 micrococcus it is separated by its sharper apex, more angular 

 margin, the position of the periproct, and the shorter pore open- 

 ings in the outer row. 



Formation and locality. — Navesink marl, bluff east of Atlantic 

 Highlands (Clark). 



Geographic distribution. — New Jersey, Alabama. 



