SHALLOW-WATER STARFISHES 207 



The whole surface is covered in life with a rather thick, soft 

 integument, containing small granules on the spines. Dorsal spines 

 mostly isolated, sometimes in small groups, conical, acute. 



Upper and lower marginal plates small, not very distinct, with 

 spines like the dorsals. Adambulacral spines in a small transverse 

 row of two to four ; the inner ones are smaller, inserted in the groove, 

 just below the margin. 



The genus Othilia Gray, December, 1840, appears to be a syno- 

 nym of Echinaster Miiller and Troschel, April, 1840. The type of 

 the latter was E. spinosus = Asterias echinophcra Lam., both by 

 virtual tautology and by designation. (See foot-note in Miiller and 

 Troschel, Syst. Ast., p. 22, 1842.) Echinaster of Gray, 1866, is 

 Acanthaster of later writers. A. echinophora Lam. appears to be 

 identical with A. spinosa Retz., 1783, the type of Othilia. The name 

 spinosus cannot be used for any species, because it was preoccupied 

 by A. spinosa Miiller, 1777. 



Fisher (op. cit., 191 ift, p. 260) separated Othilia from Echinaster 

 because it has intermarginal and sometimes, also, actinal papulae. The 

 type of Echinaster and also E. sentus (Say) have interactinal 

 papulae, as do the other American species. 



Echinaster of Fisher is probably Rhopia Gray, but he does not 

 give the type in his table. The type of the latter was R. seposita of 

 the Mediterranean. Although that was the first species mentioned 

 under Echinaster by Miiller and Troschel, April, 1840, their later 

 designation of E. spinosus, as the type, seems to settle the question of 

 the type of Echinaster. 



ECHINASTER (OTHILIA) ROBUSTUS Verrill, sp. nov. 



Disk rather large. Rays five, large, stout, rather short, obtuse. 

 Radii, 15 mm. and 42 mm.; ratio, 1:3.5. The disk is flattened in 

 drying and doubtless measures more than it would in life. 



The dorsal spines are large, conical, acute; nearly equal, isolated 

 and pretty regularly spaced, the distances between being about 

 3 mm. to 4 mm. ; height of the spines, 2 mm. to 3 mm. The papular 

 pores are numerous and have large angular or rounded papular 

 areas between. The dorsal and upper marginal spines form about 

 seven rows, but they stand nearly in quincunx, so that the rows are 

 not very distinct. 



On the actinal surface there is one row of ossicles bearing spines, 

 the inferomarginals, in contact with the adambulacrals. In this row, 

 one, two, three, and sometimes four, stand on one plate. Sometimes 



