56 Proceedings of the Eoyal Physical Society. 



Linckia marmorata (Michelin). (Figs. 1-4.) 



The specimens which we have referred to this species were at first a 

 little perplexing — in fact, from the original description and figures of L. 

 marmorata it is well-nigh impossible to distinguish the species. 



The type specimen was described by Michelin in 1844 in the Revue 

 Zoologique as Ophidiaster marmoratus, thus : — 



" 0. minima ; radiis quinis, cylindraceis, violaceis et luteolis ; parte 

 superiori longitudinaliter quinque costatis, transverse rugosis, subtilis- 

 sime granulatis, ad interstitiis varie tribus poris ornala; parte inferior i 

 granulosa ; canalibus clausis ; marginibus papillosis, duabus lineis par- 

 vulis tuberculis ornatis, tuberculo madreporiformi parvulo, rotundo, 

 sulcato, violaceo." 



In 1845 Michelin again referred to it in the Magazin de Zoologie, p. 21, 

 and also figured it (plate 10) — (" Essai d'une faune de l'ile Maurice"). 



In 1869, von Martens placed the species in the genus Linckia (Claus 

 von der Decken's Reise ; Seesterne xmd Seeigel, p. 130); while in 1875 Perrier 

 (Archiv. de Zool. Uxpe'r.) revised the species but gave little new specific 

 character to it. He notes, however, that the type specimen had the following 

 measurements : — R = 10 mm., r = 4 mm. The species was therefore established 

 on a very immature specimen. 



In 1884, Bell resuscitated the species and made a valuable contribution 

 to the specific diagnosis (Zool. Coll. of II. M.S. "Alert," p. 125). On this 

 description, and taking as a basis some specimens in the British Museum 

 which Bell has referred to this species, we have identified these puzzling 

 forms in the present collection. 



The following notes are given as a contribution towards the study of 

 this species, and should be taken in conjunction with Bell's valuable 

 variation references. 



The arms are five in number; they are subcorneal, being slightly flattened 

 on the ventral surface. 



The measurements of the different specimens in the present collection are : — 



11 = 48 



r = 9 



R =38 



r=7 



R =37 



r = 7 



A = 37 



r=7 



R = 36 



r = 7 



i2=34 



r~<5 



i.e., R = 52 to 5H r. 



