ASTEROIDEA OK NORTH PACIFIC AND ADJACENT WATERS FISHER. 265 



than in inflata, the rays bcmg decidedly broader at tlio base; R = 2 r. Tlie 

 abnctinal spines are numerous, sliarp and not arranged in <lefinite rows (except 

 marginals'), though on one ray three longitudinal series can be made out between 

 the carinnl and superomargmal series (as in extreme examples of inflata); no inter- 

 marginal spines; adambulacral spines two, round or tnincate at tip, flattened ami 

 grooved. In proportion to the size of the animal (hey are longer than in inflata. 

 Inflata differs, therefore, from tlie unnamed Japanese species in liaving a smaller 

 disk, narrower rays, more or less constricted at the base, more regular and usually 

 fewer abactinal spines, intermargmal spines fairly well developed, shorter adara- 

 buhural spines, and numerous groins in the integument of papular areas. The 

 two species are close, in fact look more alike than inflata and flerilk, and may be 

 found to intergrade over tlie intervening territory, although it is not probable, 

 since all the work in Alaska has failed to bring any S])ecimens to light. 



From P. echinastcr Perrier (equal-sized) specimens of inflata differ in having 

 longer narrower rays of a different form (echinasttr resembles the Japanese species), 

 grooved adambulacral spines, a single (not double) inferomarginal spine to each 

 plate, and longer and more regiilarly disposed abactinal spines. 



Poraniopsis mira (do Loriol) — formerly LaliUlca mira and Ortmannia mira — 

 has the grooved furrow spines of inflata, but the abactinal spines have a flattened 

 often capitate top and arc quite short and tubercular: and the ventral surface, in 

 addition lo the prominent spines, is covered with myriads of minute pricklv spine- 

 lets. As usual, de Loriol's excellent figures of specific characters render accurate 

 comparison very easy. 



PORANIOPSIS INFLATA FLEXILIS Fisher. 

 PI. .58, fig. 8; pi. 64; pi, 112, fig.'^. 

 Poraniopsis injlala flexilis Fisher, Zool. Anz., vol. 35, March 29, 1910, p. 568. 



Dia.gnosis. — Rays longer and slenderer than in inflata, very flexible and weak; 

 R = 72 mm., r = 26 mm., R=2.8 r. Breadth of raj- at base, SO mm. Abactinal 

 surface very weak owing to the slenderer skeletal elements and the larger papular 

 areas which frequently exteml from the mid-radial line to the superomarginal plates 

 without a break; meshes of actinal skeleton very wide. Spines slender, long, and 

 sharp; adambulacral spines also slender, tapering, and j)ointed and \vithout grooves. 

 No calcareous grains and tiny jilates in the integument of ])a])ular areas. 



Description. — The rays are notably slenderer than in inflata, especially at the 

 tip ; and the integument instead of being rigid is flexible. This is owing to the loose 

 skeleton and the immense ])apular areas. In the type the adrailial line of spines 

 and primarv plates is present, but the longitudinal series of intermeiliate ossicles 

 is wanting so that the two series of dorsolateral papular areas is merged into one. 

 In a specimen from 3104, which if not typical seems to be near this race, there 

 are two dorsolateral rows of i)apiilar areas so that this character may not bo constant. 

 The spines are weaker than in inflata and in seven irregular longitudinal series. On 

 account of the slenderness of tho rays distally the actinal intermeiliato plates do 

 not extend so far along the ray as in inflata- and tlie meshes of (ho skele(on are very 

 large and (lie (rabeculw slender and weak. Actinal spines few. slender, scattered. 



