88 BULLETIN 76, UNITED STATES NATIONAL, MUSEUM 



Remarks. — Although the presence of three-lobed superomarginal plates and 



broadly spatulate hand-shaped pedicellariae seems to ally atadus rather closely with 



chiroplus, I think it is perfectly distinct. It is found in shallower water than is 



chiroplus. 



Subfamily Labidiasterinae Verrill, emended 



Labidiaslerinae Verrill, Shallow-water Starfishes, 1914, p. 26. — Fisher, Starfishes of the 

 Philippine Seas, etc., 1919, p. 492; Ann. and Mag. Nat. Hist., ser. 9, vol. 12, 1923, p. 249. 



Rays numerous (9-45), long, slender; inferomarginal spines prominent, single, 

 enveloped in a sheath (carrying on the usually expanded distal surface a conspicuous 

 wreath of crossed pedicellariae) ; abactinal skeleton either very open, with large squar- 

 ish meshes, or else abortive with scattered independent plates; crossed pedicellariae 

 in abactinal spinal wreaths or thick ruffs; no actinal plates; gonads two to each ray, 

 opening upon the side a short distance from base; tube-feet numerous, biserial to 

 quadriserial, each with a single ampulla. 



Remarks. — This rather isolated subfamily contains three genera: Coronaster 

 Perrier (including Heterasterias Verrill), RatJibunaster Fisher, and Labidiaster Lutken 

 (including LabidiastreUa Verrill). A short discussion of their relationships is con- 

 tained in Fisher, Starfishes of the Philippine Seas, 1919 (p. 492). There the subfamily 

 is classified in the Pedicellasteridae. A family Pedicellasteridae consisting of Pedicel- 

 lasterinae and Labidiasterinae is convenient but probably not very natural. 



The Pedicellasterinae comprise a series of genera which lead rather naturally to 

 Tarsastrocles and to the Asteriinae proper whereas the affinities of the Labidiasterinae 

 appear to be not with the Asteriinae at all, but with the Coscinasteriinae. The 

 Coscinasteriinae and Asteriinae are two divergent lines, between which there is a 

 distinct hiatus. 



SYNOPSIS OF THE GENERA OF LABIDIASTERINAE 



a 1 . Abactinal skeleton reduced to isolated plates bearing slender acicular spines (with a thick dis- 

 tally expanded sheath, bearing large crossed pedicellariae with numerous shank-teeth and 

 enlarged lateral terminal teeth) ; alternate superomarginal plates and spines abortive; straight 



pedicellariae not spatulate, unguiculate; rays 12 to 20, very flexible Ralhbunaster Fisher. 



a 2 . Abactinal skeleton with large squarish meshes; alternate superomarginals not suppressed. 



ft 1 . Rays 9 to 11; abactinal and marginal spines acicular, prominent, solitary, rather widely 

 spaced; skeleton of outer part of ray not reduced to transverse bands of plates carrying 

 cushions of pedicellariae; large straight pedicellariae, when present, spatulate, 



unguiculate Coronaster 31 Perrier. 



b 2 . Rays upwards of 45 (25-45) ; marginal and abactinal spinelets not very prominent nor widely 

 spaced; more or less aggregated in transverse bands; skeleton of outer part of ray 

 reduced more or less to transverse arches carrying cushions of pedicellariae; straight 

 pedicellariae not large, unguiculate Labidiaster 32 Lutken. 



Genus RATHBUNASTER Fisher 



Rathbunasler Fisher, Proc. Wash. Acad. Sci., vol. 8, Aug. 14, 1906, p. 136. Type, R. cali- 

 fornicus Fisher; Bull. U. S. Nat. Mus. 100, vol. 3, 1919, p. 493; Ann. and Mag. Nat. 

 Hist., ser. 9, vol. 12, 1923, p. 249. 



Diagnosis. — In general appearance somewhat resembling Coronaster Perrier. 

 Abactinal skeleton red uced to spaced circular, independent plates (without a trace of 



» Coronaster Perrier, 1885, emended Fisher. Type C. parfaiti Perrier. See Fisher, Starfishes of the Philippine Seas, 1919, 

 p. 494. Synonyms, Stolasterias Sladen part; Heterasterias Verrill, 1914, p. 46. This genus includes C. -parfaiti Perrier, Cape Verde 

 Islands; C. antonii Perrier, Morocco; C. briareus (Verrill), off Atlantic coast of southern United States; C. octoradialas (Studer) 

 South Georgia Island; C. volsellatus Sladen, Philippine Islands. C. halicepus Fisher, Philippine and Molucca Islands; C. eclipes 

 Fisher, Hawaiian Islands. (Sea Stars of Tropical Central Pacific, Bishop Mus. Bull. No. 27, 1925, p. 86, fig. 9a). 



» Labidiaster Lutken, 1871. Typo L. radiosus Lutken. Synonym LabidiastreUa Verrill, 1914, p. 352. This genus includes 

 L. radiosus Lutken, southern end of South America, south to 64° 48" S.; L. annulatus Sladen, South Pacific north to Aru Islands; 

 L. crassus Koehler, Antarctic. 



