WEST INDIAN STARFISHES 



19 



(peractinal) raw, like the lower marginals, but they may be rudi- 

 mentary and spineless in half-grown specimens, and only bear 

 spines in large, mature individuals, as in C. tenuispina. 



Minor pedicellariae are abundant. Large forficulate or major 

 pedicellariag of the usual forms are present, often in considerable 

 numbers, on the dorsal and lateral plates, and smaller ones occur 

 on the marginal areas. Large unguiculate pedicellarige are lack- 

 ing. Adambulacral plates are monacanthid or nearly so. 



Stolasterias, which was proposed as a subgenus by Sladen in 

 1889, was nearly identical with Coscinasterias, characterized by 

 me in 1867. He gave no reason for changing the name. It 

 should be regarded as a synonym of the latter and be eliminated. 

 Sladen 's type was A. tenuispina, which is a Coscinasterias with 

 the interactinal plates rudimentary and without spines, except 

 in the larger specimens. 



As C. tenuispina often divides spontaneously, it belongs to 

 Polyasterias in Perrier's arrangement. This would make the lat- 

 ter strictly synonymous with Sladen 's typical Stolasterias. 



M. Perrier (1894) correctly retained Coscinasterias for the 

 typical forms, like calamaria, but separated those species that 

 are known to undergo spontaneous fission under the name of 

 Polyasterias = typical Stolasterias Sla., though they do not ap- 

 pear to differ much in structure from the preceding. He re- 

 tained Stolasterias Sla., in a restricted sense, for those allied to 

 glacialis, although C. tenuispina was named by Sladen as the 

 type. 



A. glacialis had, long before, been made the type of Marthas- 

 terias by Julien. 



Coscinasterias tenuispina (Lam.) Ver. 



Asterias tenuispina Lamarck, op. cit., 1816, vol. ii, p. 561. Perrier„ Ke- 



vision, op. cit, p. 306, 1875. 

 AsteracantMon tenuispinus Miill. and Trosch., Syst. Asteriden, p. 16, pi. i, 



fig. 1, a. b., 1842. Perrier, Pedicellaires, p. 32, pi. i, figs. 3-3c, 1859. 



Liitken, op. cit., 1859, p. 95. 

 Asterias (Stolasterias) tenuispina Sladen, pp. 565, 583, 1889. Verrill,, The 



Bermuda Islands, vol. ii, part v, p. 324, in Trans. Conn. Acad. Sci., 



vol. xii, p. 280, plates xxxiv, fig. 2 ; xxxiv c, fig. 2, 1907. 

 Coscinasterias tenuispina Verrill, op. cit., 1814a, p. 45. 



Asterias atlantica (pars) Verrill, Transactions Conn. Acad. Sci., vol. i, p. 

 368, 1868. E.. Eathbun, Brazilian Echinoderms, in Trans. Conn. Acad., 

 vol. V, p. 144, 1879. 



