152 NATURAL HISTORY BULLETIN 



generally covered with highly developed true paxillae (sometimes 

 with parapaxillae or pseudopaxillge), covering fasciolated inter- 

 spaces, lodging intervening simple papulae. 



Marginal plates of both rows are usually large, thick, and 

 paired. The inferomarginals are often the larger transversely. 

 They are either granulated or spinulose and often very spinose, 

 with more or less simple fasciolated grooves between them, but 

 never covered by a thick skin. Adambulacral plates are usually 

 spinose or spinulose on the actinal surface and have a divergent 

 row of furrow-spines, without a web. 



Pedicellarige are often lacking; when present they are usually 

 fasciculate or papilliform, often consisting of two to four short, 

 slender, connivent spinules, surrounding a special pore or pit. 

 Ambulacral feet in two rows, large, usually pointed, never with 

 suckers. Ampullae double. Dorsal glands and pore usiialty 

 present. Superomarginal plates always present. 



Interactinal plates sometimes wanting ; often more or less num- 

 erous and arranged in regular rows ; usually spinulose and with 

 fasciolated grooves between the rows, but without marginal 

 webs ; f ascioles are sometimes lacking. 



The aproctous condition, formerly supposed to be characteris- 

 tic of the family, is unreliable, for in nearly all the genera re- 

 ferred to it there is a perfectly well defined dorsal or ''anal" 

 pore, and in some of the genera the pore is even elevated on the 

 summit of a dorsal cone or chimney {Psilaster, Ily aster, etc.) 

 This pore, which I have designated as ' ' pseudanus ' ' or ' ' nephri- 

 dial pore/' serves in this family (and in many others) chiefly 

 if not entirely, for the discharge of the secretions of the lobulat- 

 ed dorsal gland (probably nephridial in function.) 



Genus Astropecten Gray (emended). 



Astropecten (pars) Gray, Ann. and Mag. Nat. Hist., vol. vii, p. 180, 1840 ; 



Synopsis, p. 3, 1866. Miill. and " Trosch., Syst. Aster., p. 67, 1842. 



Sladen, op. cit., 1889, p. 193. Fisher, op. cit., 19115, p. 55. Verrill, 



op. cit., 1914a, p. 317. 

 Stellaria Nardo, Oken's Isis, p. 716, 1834, (non Miiller, 1832, Mollusca). 

 Asterias L. Agassiz, Prod., p. 191, 1835. 



Rays more Or less elongated, subacute, flat above, with true, 

 abactinal, coronate or stellate paxillae, and large, stout, paired 

 and fasciolated marginal plates. The superomarginals are con- 



