A. E. Verrill — Revision of the Genera of Starfishes. 477 



Art. XL. — Revision of the Genera of Starfishes of the Sub- 

 family Asterinince ; by A. E. Merrill. 



There is, perhaps, no family of starfishes that is so much in 

 need of revision as the Asterinidge. Even in recent standard 

 works very erroneous statements are made as to the mor- 

 phology of the group* and the characteristic structures of the 

 genera and subfamilies, f while very diverse species are still 

 included in the old genus Asterina. In this brief article I 

 propose to give a summary of the classification of those Aster- 

 ininge more nearly allied to Asterina proper, and in part 

 usually referred to that genus, but it is not possible to classify 

 all the numerous species at this time. The group is well 

 represented in all the warmer seas, but no species is found on 

 our Atlantic coastj north of Florida, except the large and very 

 aberrant species, Tremaster mirabilis Yer., often made the 

 type of a separate subfamily. It is from the northern fishing 

 banks. Only one is found on the Pacific coast north of south- 

 ern California, viz., Patiria miniata (Br.). 



Subfamily Asterinin^. 



Asterinidce (pars) Gray, Ann. and Mag. N. Hist., vi, p. 228, 1840 ; Synopsis, 

 p. 15, 1866. Perrier, Revis. Stell., iv, p. 291, 1875; v, p. 209, 1876. 

 Viguier, Squellette des Stell., Arch. Zool. Exper., vii, p. 205, pi. xiv, 

 figs. 1-13, 1878 (structure). Sladen, Voy. Challenger, xxx, p. 374, 

 1889. Perrier, Expl. Trav. et Talism., pp. 141, 163, 1894. Fisher, op. 

 cit., 1911, p. 253 (table of genera). 



Body usually rather flat, often thin, sometimes stellate with 

 long rounded rays ; usually with five or six short rays, rarely 

 eight. Margins usually thin and formed mainly by the infero- 

 marginals ; marginal plates small, usually scarcely larger than 

 the adjacent dorsals, usually with a comb or cluster of spinules. 

 Dorsal plates usually flat and more or less imbricated, some- 

 times not imbricated ; generally covered with minute spinules, 

 often in tufts or combs ; sometimes covered with a soft, naked, 

 or granular dermis. Under side flat ; actinal plates angular, 



* Thus Gregory, 1900, in Lancaster's Treatise on Zoology, p. 238, ei'rone- 

 ously states that the madreporic plate is on the ventral side in Asterina, and 

 on page 250 gives as family characters, the absence of pedicellariee ; imbri- 

 cated plates ; and other characters of only generic value. 



f Sladen, Voy. Challenger, 1889, p. 374, and Fisher (Asteroidea of N. 

 Pacific, 1911, p. 253), are both in error in stating that the papulae are gener- 

 ally distributed, and that the dorsal plates do not have descending processes 

 or pillars in Asterininaa, while these characters exist in Anseropodinse. In 

 fact, the papula? are always definitely localized, and many typical Asterininas 

 (e. g. Patiria) have strong vertical pillars. 



% The small specimen formerly described by me, from off the coast of 

 Maine, as Asterina pymcea , proves to be the young of a Porania. 



