282 CRETACEOUS PALEONTOLOGY. 



The dimensions of a complete individual, as indicated by the 

 size of a nearly complete interambulacral area, are : height, about 

 25 mm. ; width .about 37 mm. 



Remarks. This species occurs with C. splcndens, but is much 

 less common. It ordinarily occurs as detached plates, and these 

 may be easily distinguished from those of C. splcndcns by reason 

 of the broader miliary areas and the imperforate mamelon. 



Formation and locality. Vincentown limesand, Vincentown 

 (154), Timber Creek (Clark). 



Geographic distribution. New Jersey. 



Order DIADEMATOIDA. 

 Family SALENIIDAE. 

 Genus SALENIA Gray. 



Salenia tumidula Clark. 

 Plate VIII.. Figs. i-io. 



1891. Salenia tumidula Clark, Johns Hopkins Univ. Circ., voL 



10, No. 87, p. 75. 

 1893. Salenia tumidula Clark, Johns Hopkins Univ. Circ., voL 



12, No. 103, p. 51. 

 1893. Salenia tumidula Clark, Bull. U. S. G. $., No. 97, p. 41, 



figs. la-j. 

 1905. Salenia tumidula Johns., Proc. Acad. Nat. $ci. Phil., 



1905, p. 6. 



Description. Test small, subglobose, the ventral surface flat, 

 becoming depressed towards the oral opening, the sides inflated 

 and regularly curved, passing into the convex dorsal surface. 

 Ambulacra! areas nearly straight, narrow, slightly increasing in 

 width from the apical disk to the oral opening, with two rows, 

 15 or 1 6 each, of mamillated granules between the poriferous 

 zones and between these, other minute granules; poriferous 

 zones narrow and very slightly flexed; the pores circular, 

 regularly arranged in unigeminal series, those in the middle 

 of the test the largest. Interambulacral areas with five or six 

 plates in each row, with indistinctly marked sutures; the larger 



