ECHINODERMATA. 283 



tubercles diminish rapidly in size toward the oral margin, be- 

 coming very indistinct on the plates bordering the same; each 

 areola is large and circular, the boss crenulated and the'mamelon 

 flattened and imperforate; the miliary space is bordered with oval 

 granules of irregular size and arrangement, becoming most nu- 

 merous between the rows of tubercles. The apical disk large, 

 prominent, subcircular, with a regularly curved convex surface; 

 the granular decorations of the surface often coalesce and appear 

 as broken ridges extending radially from the five openings in 

 the genital plates; the anal opening is oval, slightly pointed be- 

 low, it is bordered by a flange-like edge formed by the anal 

 and two genital plates which project slightly above the surface 

 of the disk. The oral opening is small, occupying scarcely two- 

 fifths"of the diameter of the test; ten incisions divide the margin 

 into lobes, the ambulacral lobes projecting the farther. 



The dimensions of a complete individual are : height, 9.4 mm ; 

 width, 12.5 mm. 



Remarks. — This species most closely resembles S. hellula with 

 which it is associated, but it has a more globular test, and the 

 granules of the interambulacral plates are oval instead of cir- 

 cular. From S. texana it may be distinguished by the smaller 

 number of mamillated granules of the interambulacral areas and 

 by the far less strongly projecting anal opening. 



Formation and locdity. — Vincentown limesand. Timber Creek 

 (Clark). 



Geographic distribution. — New Jersey. 



Salenia bellula Clark. 

 Plate VIII., Figs. 11-17. 



1891. Salenia bellula Clark, Johns Hopkins Univ. Circ, vol. 10, 



No. 87, p. 75. 

 1893. Salenia bellula Clark, Johns Hopkins Univ. Circ, vol. 



12, No.. 10.3. p. 51. 

 1893. Salenia. bellula Clark, Bull. U. S. G. S., No. 97, p. 43, 



pi. II, figs. 2 a-g. 

 1905. Salenia bellula Johns., Proc. Acad. Nat. Sci. Phil., 1905, 



p. 6. 



