ASTEROIDEA OF NORTH PACIFIC AA'D .VDJACKNT WATERS — FIrillEH. 261 



KEY TO THR SPECIES OP POKANIOrSIS HEREIN' OES< KinED. 



Adambulacral spines with a groove; rays rigi<l and Hkelotnn Hti»iii; iiiJra<llal row of intcrnu-diate Oflgiclee 

 always present infiata. 



Adambulacral spines tapering without a groove; rays weak and flexible; adradial series of iotermediate 

 ossicles sometimes absent fleiilii. 



Remarls. — This gcuus diiTers from Echintister in lacking a spinelct on the furrow- 

 face of the adambulacral, and in having the madreporic body an independent plate. 

 The skeleton is very much more open than in either Kckinasier or Olhilia, the reticu- 

 lations being comparatively few and large. Lu<lwig (1005, p. 210) mentions as 

 another difference from Echinasier the presence of intermarginal jiapular areas, but 

 this will not hold unless Othilia is recognized as independent, since Echinaster sentus, 

 spinosus, and spinuhsus have intermarginal papulje, ami spinuhsus has actinal 

 papulae. The type of Othilia is Asterias spinosa Retzius, ISO.t (Eclnnaster spinosus 

 Muller and Troschel, 1S42) Brazil. 



I think a comparison of descriptions and figures will convince an\- one that 

 Perrier's Poraniopsis, de Loriors Lahillca, and Ludwig's Ahxandraula- are the same 

 genus. At any rate there are absoluteh' no differences of generic importance, 

 AlexandraMer »wrus being even specifically close to Poraniopsis eclnnaster. Perrier's 

 comparison of Poraniopsis with Porania is certainly misleading for the resemblance 

 is most superficial. The name, Poraniopsis mira (de Loriol, 1904) invaUdates 

 P. mira (Ludwig, 1905). The latter is doubtfidly distinct from ray flexilis. 



I did not see de Loriol's paper until after I described " Ahxandraster" injlatus 

 (June 1906) when the identity of the two genera became evident at once. De 

 Loriol published several good figures. A further search brought to light Poraniopsis, 

 which so far as I know is the oldest name. 



PORANIOPSIS INFLATA (Fisher). 



PI. 58, figs. 7, 7a; pi. 63, figs. 1, 2; pi. 112, fig. 1. 



Aleiandraster injlaius Fisher, Zool. Anz., vol. 30, June 19, 1906, p. 300. 

 Poraniopsis inflata Fisher, Zool. Anz., vol. 35, March 29, 1910, p. 569. 



Diagnosis. — Rays short, robust, evenly tapered or sUghtly inllated at laidiilc. 

 bluntly pointed; disk capable of consiilerable inflation; whole animal appearing 

 inflated and turgid. Tj^ie, R = 60 mm.; r = 2.3 mm.; R = 2.6 r; breadth of ray at 

 base, 27 mm. Skeleton forming large squarish or polygonal areas (occupied by verj- 

 numerous papulic), the whole covered by a rather thick skin mounting the base of 

 the upright, usually sharp, prominent spines which stand at the corners of the 

 papular areas; counting around the riiy from inferomarginal to inferoinarginal 

 series inclusive there are seven more or less regular longitudinal rows of spines in 

 type but as many as thirteen in a few Itirge specimens, the e.xtra spines being shorter 

 and forming rows interpolati^d between the primary series; adambulacral plates 

 with two prominent grooved spines in a transverse series; actinal intermediate 

 spines, often grooved ; no actinal papuhv. 



Description. — Abactinal and lateral skeleton compose<l of three or four lobed 

 primary plates connected by several elliptical oblong overlapping ossicles forming a 

 large mesh, inclosing spacious subquadrate and iiTegular papular spaces, which 



