298 CRETACEOUS PALEONTOLOGY. 



Cardiaster smocki n. sp. Clark. 



Plate XIII., Pigs. 9-11. 



Description. — Test small, cordate, distinctly elevated, the 

 dorsal surface strongly convex, the ventral surface flat. The 

 anterior ambulacral sulcus is very pronounced and the opposite 

 ridge in the unpaired posterior interambulacrum is well shown 

 but is sharply cut off by the nearly vertically truncated surface 

 of the posterior margin. The sides slope rapidly to the ambitus. 

 Ambulacral areas wide, apetaloid and well separated at the apex ; 

 antero-lateral pair bent backward above, beyond which they 

 extend straight to the ambitus; the posterior-lateral pair are 

 bent slightly forward at first and then continue in a straight line 

 over the margin ; the unpaired ambulacrum situated on the deep 

 anterior sulcus. Apical system much elongated, widely Separ- 

 ating the ambulacral areas. The peristome transversely oval, 

 situated anteriorly. 



The dimensions of the type specimen are: length, 18.5 mm.; 

 width, 17.5 mm.; height, 10 mm. 



Remarks. — This species is most closely related to Cardiaster 

 cinctus, but it is a smaller form with somewhat less pronounced 

 anterior sulcus and more inflated test. 



Formation and locality. — Merchantville clay-marl. (Clark.) 



Geographic distribution. — New Jersey. 



Family SPATANG-IDAB. 



Genus HEmiaster Desor. 



Hemiaster parastatus (Morton). 



Plate XV., Figs. 1-13. 



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



p. 286. 

 1830. Spatangus cor-marinum (?) Mort., Am. Jour. Sci., ist 



ser., vol. 18, p. 250, pi. 3, fig. 10. 

 1830. Spatangus cor-marinum ( ?) Mort., Jour. Acad. Nat. Sci. 



Phil, 1st sen, vol. 6, p. 199. 



