ECHINODERMATA. 301 



of the test covered with innumerable small tubercles, between 

 which are microscopic granulations ; the peripetalous fascicle 

 distinct, oval, passing with a regular curve about the extremities 

 of the petaloid areas. Apical disk small, situated posterior to 

 the center of the dorsal surface but in front of the apex of the 

 test. Oral opening transversely subelliptical, bilabiate, situated 

 near the anterior margin. Anal opening small, oval, situated at 

 the upper part of the posterior truncated surface. 



The dimensions of a complete individual are : length, 25 mm. ; 

 width, 21.9 mm.; height, 15.6 mm. 



Remarks. This species may be easily distinguished from other 

 American members of the genus by reason of its short anterior 

 sulcus which terminates before reaching the margin, so that the 

 anterior margin of the test is not emarginate. 



Formation and locality. Vincentown limesand, Timber Creek 

 (Clark). 



Geographic distribution. New Jersey. 



Hemiaster ungula (Morton). 

 Plate XVI., Figs. 5-11. 



1830. Spatangus sp. Mort., Am. Jour. Sci., ist ser., vol. 17, p. 

 286. 



1833. Spatangus ungula Mort., Am. Jour. Sci., ist ser., vol. 23, 



p. 131, pi. 10, fig. 6. 



1834. Spatangus ungula Mort., Synop. Org. Rem. Cret. Gr. U 



S., p. 78, pi. 10, fig. 6. 

 1891. Hemiaster ungula Clark, Johns Hopkins Univ. Circ., vol. 



10, No. 87, p. 77. 

 1893. Hemiaster ungula Clark, Johns Hopkins Univ. Circ., vol. 



12, No. 103, p. 52. 

 1893. Hemiaster ungula Clark, Bull. U. S. G. S., No. 97, p. 85, 



pi. 46, figs. 2 a-g. 

 1905. Hemiaster ungula Johns. Proc. Acad. Nat. Sci. Phil., 



1905, P- 7- 



Description. Test ovate, distinctly cordate, the ventral sur- 

 face flat, except the peristomal depression, the dorsal surface 



