66 ASTER0IT)EA. 



do not extend far into the rays, are closely covered with sharp 

 spiniform granules. The marginals are short but quite distinct, 

 and the superomargiuals, though much less wide than the infero- 

 marginals, remain distinct to the top of the arm. They are both 

 covered by large granular plates, which sometimes take on the 

 appearance of spiues ; there are from 20 to 40 marginals on either 

 side of each arm. The dorsal surface formed of the ends of fine 

 paxillse, the form of which is obscured by the integument which 

 invests them. 



Colour : dry or in spirit, white ; alive, cinnabar to orange. 



Distribution. East and western sides of northern part of Atlantic 

 to Arctic Ocean. 20-690 fms. 



a, b. Faeroe Channel, 1312 fms. ' Porcupine ' Exp. (St. 82). 



c, d. Between Faeroe and Shetland, 640 fms. ' Porcupine ' Exp. (St. 65). 



2. ASTROPECTEN. 



Astropecten, C. F. Schidtze, Betrachtung rersteiner. Seesterne, (1760) 



p. 50 ; Gray, Ann. Sr Mag. vi. (1840) p. 180 ; M. Tr. Syst. Ast. 



(1842) p. 67 ; Norm. Ann. $ Mag. xv. (1865) p. 115 ; Terr. Arch. Zool. 



exp. iv. (1875) p. 302 ; Vignier, op. cit. vii. (1878) p. 231 ; Sladen, 



Chall. Rep. Ast. 1889, p. 175. 

 Stellaria, Nardo (non Mbller), Isis, 1834, p. 716. 

 Asterias, Ag. (?wn Linn.). Mem. Soc. Neuch. i. (1836) p. 191 ; Forbes, 



Mem. Wern. Soc. viii. (1839) p. 118; M. Tr. Arch. f. Nat. 1840, 



p. 323. 

 Crenaster, d'Orb. Trodr. Tal. i. (1849) p. 240. 



An Astropectinine in which there is no webbed marginal fringe ; 

 the supermarginal plates have a prominent ridge, all the marginals 

 are more or less quadrate in form, and those of the upper series are 

 nearly of the same size as those of the lower. 



Key to the Species. 



Marginals with rectangular sides 1. A. irregularis. 



Marginals wedge-shaped 2. A. sphenoplax. 



1. Astropecten irregularis. 



Asterias irregularis, Fenn. Brit. Zool. iv. (1777) p. 52, no. 57. 

 Astropecten irregularis, Gray, Ann. fy Mag. vi. (1840) p. 182; id. 



Brit. Fad. (1848) p. 18; Duj. $ Hup. Ech. (1802) p. 414; 



Norman, Ann. ty Mag. xv. (1865) p. 116; Hodge, Tr. Northumb. 



$ Durh. iv. (1872) p. 133 ; Perr. Arch. Zool. v. (1876) p. 288 ; 



Kor. Sf Fan. Norske Nordhavs Asteroidea, (1884) p. 82 ; Sladen, 



Chall. Rep. Ast. (1889) p. 209. 



