284 CRETACEOUS PALEONTO'LOGY. 



Description. — Test small, compressed, the ventral surface flat 

 or slightly concave at the oral opening, the sides inflated, the 

 upper suftace regularly convex. Ambulacral areas rather broad, 

 prominent and nearly straight, changing but slightly in width 

 from the apical disk to the margin of the oral opening ; two rows 

 of mamillated granules, 15 in each row, occupy the center of 

 each area between the poriferous zones and between these other 

 minute granules are present ; poriferous zones broad, very slightly 

 flexed; pores circular, unigeminal. Interambulacral areas wide, 

 with five or six plates in each row; the tubercles prominent, 

 decreasing rapidly in size toward the margin of the oral opening ; 

 the areola oif moderate size, the boss , narrow and indistinctly 

 crenulated, the miamelon small, flattened and imperforate; an 

 interrupted row of circular, mamillated granules surrounds each 

 tubercle, and between the rows of tubercles these granules unite 

 tO' fonn a sinuous, double series; between the larger granules 

 numerous smaller ones are scattered irregularly, being crowded 

 together along the central line of the interambulacral area. 

 Apical disk nearly circular, slightly convex, the plates decorated 

 with oval granules arranged in radial rows extending from the 

 opening of each genital plate and uniting with the corresponding 

 rows of adjacent plates at the suture; the anal opening sub- 

 circular, with a flange-like rim, . interfering but little with the 

 regularity oif the curved surface. The oral opening small, being 

 but one-third the transverse diameter of the test, its margin 

 divided by 10 slight incisions into lobes of nearly uniform size. 



The dimensions of a complete test are : height, 6 mm. ; width, 

 10 mm. 



Remarks. — ^This species is closely allied to the last, but is 

 more depressed, has a differently decorated apical disk, and has 

 circular granules in the miliary space instead of oval. 



Pormation and locality. — Vinceiitown limesand, Vincentown 

 (154), Timber Creek (Clark). 



Geographic distribution. — New Jersey. 



