JAPANESE ASTEROIDEA. 483 



larise, for they not only cover the reticulating bars of the dorsal ossicles, but 

 invade also the poriferous areas ; the granules, of ordinary character, are 

 confined to the knobs and spines, the tips of which, however, they do not 

 cover. Along the lopliial line the projections are always rather tubercular 

 than spinous, but the five spines at the angle of the apex and the central 

 spine within are exceedingly well developed and rather acutely pointed. A 

 few rounded tubercles, similar in character to those of the lophial line, are 

 developed at the sides of the disk. In dried specimens the disk rises up in 

 an altogether turriform fashion. Madreporite small, rather obscure, on one 

 of the sides of the disk. 



" Colom* (dried) greyish sandy. 



" Hab. Indian Ocean generally. 



" Measurements : — 



Ft 165 130 118 100 [mm.] 



r 62 44 46 87 



Height of disk 58 45 31 27 



Length of longest spine . . 15 14 21 18 



"It is to be observed that there are some not unimportant variations in 

 the characters of the spines, those of the lophial line are sometimes sharp, 

 are not alwa^'s blunt ; the apical spines appear to be liable to early division 

 into two or tin'ee secondary apices, or they may give off a spm' or projec- 

 tion, and, lastly, the processes at the sides of the disk ma^^ become quite 

 sliarp." 



Bell ['84 a, p. 128] mentions some " fine specimens from Port Denison, 

 4 fms." 



Studer refei-s to this species at length under the name of P. turrltm 

 LiNCK and points out the occmTence of sexual dimorphism ['84, p. 39] : 



" Diese Art fand sicl\ im Clreetharbom- in Neu-Britannien imgemein 

 zalJreich vor. Die tauchenden Eingebornen brachten die Art aus 1 Faden 

 Tiefe in grosser Menge. Es Hessen sich unter den zalilreichen Exemplaren 

 zwei Formen unterscheiden. Die eine mit relativ niedriger Scheibe und festem 

 ♦Skelett, mit einer Warze neben dem After im Centrum der Scheibe. Die 

 Farbe der Oberseite ziegelroth, die Höfe um die Warzen schwarzbraun. Sie 



