1888.] NATURAL SCIENCES OF PHILADELPHIA. 423 



P. Dance, Verrill. Proc. Bost. Soc. Nat. Hist. vol. xii, p. 386 ; 



Trans. Conn. Acad. vol. i, p. 568, pi. IX, figs. 11, 11a. 

 P. affinis, E. A. Smith. Ann. Nat. Hist. (4), vol. xvii, p. 108. 

 P. rugatus, Sladen. Journ. Linn. Soc. vol. xvi, p. 195. 

 P. stellifer, Sladen. Journ, Linn. Soc. vol. xvi, p. 195. 

 JR. semireticulatus, Sladen. Journ. Linn, Soc. vol. xvi, p. 195. 

 P. carlbbceus, Perrier. Comptes Rendus xcii, p. 59 ; Bull. Mus. 



Comp. Zool. ix, p. 13 ; Nouv. Arch. Mus. (2) vi, p. 216. 

 P. ajwrus, Ludwig. Zoologische Jahrbiicher 1886, p. 293. 



Coronaster bispinosus, n. sp. 



Twelve long slender arms. 

 . Dorsal skeleton of disk reticulated ; formed of imbricated ossicles, 

 and enclosing irregularly shajied meshes in which are found from 

 four to ten respiratory tubes. Distributed irregularly on the skele- 

 ton of the disk are short spines, each bearing a little cluster of cross- 

 ed pedieellarise. Madreporic plate small and submarginal. 



Dorsal skeleton of arms reticulated : Reticulation formed by 

 five longi'tudinal bands of imbricated ossicles, connected at about 

 •every fourth plate by similar transverse bands, forming large rec- 

 tangular meshes. Meshes longest in the direction of the arms, con- 

 taining a large number of tentacular papillse. Sometimes closer and 

 irregular in shape at the base of the arms. At the junction of the 

 longitudinal and transverse bands, stand long pointed spines, each 

 spine surrounded about its middle by a closely packed cluster of 

 crossed pedieellarise. 



Each of the adambulacral plates carries an inner and outer spine, 

 the outer spine being slightly more adoral than the inner one, thus 

 showing a tendency of the two spines to alternate. 



Length fz-om centre of disk to end of arm, 140m; radius of disk, 

 12m. 



Color of the single specimen in alcohol pale flesh color, with the 

 skeletal portions white. 



This form undoubtedly belongs to the genus Coro?ia5fer of Perrier 

 (Echinodermes du Travailleur et du Talisman, Annates des Sciences 

 Naturelles, VI? Serie, T. XIX, No. 8, 1885.) He gives, however, as 

 a character of the genus the existence of a single spine on each ad- 

 ambulacral plate, wdiereas in Coronaster bispinosus there are two 

 such spines to each plate. This character of the genus must there- 

 fore be modified in order to admit this species. 



