102 BULLETIN 76, UNITED STATES NATIONAL MUSEUM 



be mentioned the following: The very large double-fanged pedicellariae of forreri 

 and the presence of these on the inner inferomarginal spines; the rudimentary 

 character of the actinal plates which never carry spines. 



Genus DISTOLASTERIAS Perrier 



Plate 60, Figures 1, la-Id, 3 



Distolasterias Perrier, Result, campag. sci. du Prince de Monaco, fasc. 11, 1896, p. 34. Type, 

 Asterias {Stolasterias) stichanlha Sladen. — Fisher, Ann. and Mag. Nat. Hist., ser. 7, vol. 

 17, 1906, p. 574; Starfishes Hawaiian Islands, 1906, p. 1105 (subgenus including 

 Sclerasterias) ; Starfishes of the Philippine Seas, 1919, p. 487 (genus, including Scler- 

 asterias). — Verrill, Shallow - water Starfishes, 1914, pp. 47, 185 (genus including 

 Lethasterias) . 



Diagnosis. — Resembling Sclerasterias in having diplacanthid adambulacral 

 plates, but differing in having on the inner as well as on the outer of the two infero- 

 marginal spines a cluster of crossed pedicellariae; dorsolateral plates in more than a 

 single series; crossed pedicellariae with two enlarged terminal teeth on each jaw, 

 conspicuously larger than the median terminal teeth; normally a spine on each 

 superomarginal (and carinal) plate; no specialized area of pebbling on superomarginals; 

 actinal plates small, spineless, hidden under thick integument of actinal surface. 



Remarks. — Perrier first used this name in a summary key to take care of those 

 species of Coscinasterias with two adambulacral spines. No other peculiarities were 

 indicated and the group apparently left no great impression, since a few pages further 

 on he placed the diplacanthid Stolasterias neglecta in a genus specially characterized 

 by monacanthid adambulacral plates; that is to say, in a group headed by Asterias 

 glacialis, for which a kidnapped name, for some unexplained reason, is chosen. 



The sense in which the writer employed the name in 1906 and 1919 corresponds 

 to Sclerasterias of this work; while Verrill used the name in the sense of Lethasterias. 



The known species are: Distolasterias stichantha (Sladen), 345 fathoms, off Japan; 

 D. robusta (Ludwig), Galapagos Islands, 385 fathoms; D. nipon (Doderlein), Sea of 

 Japan to Hong Kong. 



In my "Preliminary Synopsis," the predominant straight pedicellariae of 

 Distolasterias were said to be small, slender lanceolate. This is true of D. nipon 

 and D. robusta but not of D. stichantha, the type of which I later had the privilege 

 of examining. (See pi. 60, figs 1, la-Id.) Scattered over the abactinal and lateral 

 surfaces are bivalved hand-shaped pedicellariae, an especially large one (in two 

 interradii, two) occupying the actinal interradial area. Another slightly smaller 

 one may stand near the first or second inferomarginal spine. The abactinal are 

 1.5 to 1.8 mm. long and the large interradial ones are 2.2 mm. long. In D. stichantha 

 the abactinal spines are not always in such neat rows as figured, 36 although on one 

 ray this is true. The adoral carina is composed of two pairs of postoral adambulac- 

 ral plates, the plates of the outer pair not wholly in contact, since the distal ends 

 diverge. The plates of the third pair are rather widely separated. There is a series 

 of small spineless actinal plates hidden by the integument. 



Distolasterias differs from Lethasterias in having prominently fanged straight 

 pedicellariae; fewer, less crowded, dorsolateral plates; an odontophore with a single 

 pit or depression on the outer border. 



15 Sladen, Challenger Asteroidea, 1880, p. 586, pi. 106. 



