ECHINODERMATA. 303 



terminating in a well-defined, truncated posterior surface. 

 Ambulacral areas moderately depressed in the petaloid portions ; 

 the postero-lateral pair considerably shorter than the antero- 

 lateral, although the difference is less marked than in other New 

 Jersey Cretaceous species of the genus ; the anterior ambulacrum 

 situated in a broad, shallow groove that largely disappears before 

 the ambitus is reached. Apical system small, imperfectly shown 

 on the casts. Peristome of moderate size with distinct overhang- 

 ing lip. Periproct small, situated high on the truncated posterior 

 surface. 



The dimensions of the type specimen are : length, 27 mm. ; 

 width, 24 mm. ; height, 17 mm. 



Remarks. — This species is related to H. parastatus, from 

 which, however, it is separated by its less deeply depressed 

 ambulacral furrows and less elevated dorsal surface. It also 

 shows points of resemblance to H. kUmmeli, from which, how- 

 ever, it is separated by its longer postero-lateral ambulacral 

 petals and less elevated posterior ridge on the dorsal surface. 



Formation and locality. — Merchantville clay-marl, near James- 

 burg (139,141), Lenola (163); Navesink marl, bluff east of 

 Atlantic Highlands (Clark). 



Geographic distribution — New Jersey. 



Hemiaster kUmmeli n. sp. Clark. 

 Plate XVII., Pig. 1-3. 



Description. — Test cordate, rather large^ slightly elevated, the 

 dorsal surface nearly flat, ventral surface flat. The posterior 

 interambulacrum nearly flat with a low truncated posterior sur- 

 face. Ambulacral areas pronounced, with weakly depressed 

 petaloid areas ; the petals O'f the postero-lateral pair relatively long 

 and narrow; less than twice the length of the antero-lateral pair; 

 the unpaired ambulacrum not deeply depressed, and not forming 

 a pronounced sulcus on the anterior margin. The apical system 

 small, not as strongly eccentric as in some of the other Cretaceous 

 species. Peristome with a distinct overhanging lip, the periproct 

 not seen. 



The dimensions are : length, 30-50 mm. ; width, 30-40 mm. ; 

 height, about 20 mm. 



