358 THE VOYAGE OF H.M.S. CHALLENGER. 



Gymnasteria inermis, Gray, 1840, Ann. and Mag. Nat. Hist., vol. vi. p. 278. 



Asteropsis carinifera, Muller and Troscliel, 1842, System der Asteriden, p. 63. 



Gymnasterias carinifera, v. Martens, 1866, Arcliiv f. Naturg., Jahrg. xxxii. Ld. i. p. 74. 



? Gymnasterias biserrata, v. Martens, 1866, Arcliiv f. Naturg., Jahrg. xxxii. Bd. i. p. 74 (anjuv.). 



Locality. — Off Kandavu, Fiji Islands. On the Reefs. 



Remarks. — Two adult examples (presenting the well-known characters of this form), 

 and one young one, were collected by the Challenger at the above-named locality. I 

 have given drawings of the young specimen (see PI. LIL figs. 5-8), in order to show the 

 presence of spinelets on the infero-marginal plates, and their absence along the median 

 line of the ray : a state of things exactly the reverse of what occurs in the adult condition. 

 This circumstance leads me to believe that the form described by von Martens as speci- 

 fically distinct under the name of Gymnasteria biserrata, is only the young stage of 

 Gymnasteria carinifera, or at most only a variety in which the juvenile characters are 

 maintained throughout life. 



Valuable observations on the growth stages of this species, as presented by a series of 

 examples from Mauritius, have been made by de Loriol, 1 who has also given figures, 

 with which it will be interesting to compare those on PL LIL of the young example from 

 Kandavu. 



It may be remarked that some variation occurs in the spinulation of the infero-margi- 

 nal plates of adult specimens from different localities. Normally in fully grown examples 

 these plates bear no trace of spines, but in large specimens from the Red Sea (winch 

 are amongst Muller and Troschel's types in the Berlin Collection), traces of a few incipient 

 spines are present on the outer part of the ray. Also in examples from Mozambique and 

 from Timor the occasional spinulation of the infero-marginal plates is more pronounced. 

 I do not, however, look upon these as anything more than local, and perhaps even 

 individual, variations. 



Genus Porania, Gray. 



Goniaster (pars), Forbes, Mem. Wern. Soc, 1839, vol. viii. p. 118. 

 Porania, Gray, Ann. and Mag. Nat. Hist., 1840, vol. vi. p. 288. 

 Asteropsis (pars), Muller and Troschel, System der Asteriden, 1842, p. 62. 



This well-marked genus was established by Gray in 1840, and the name he proposed 

 has an incontrovertible claim for acceptance. Notwithstanding this, some recent writers 

 have followed the terminology of Muller and Troschel, and have used the name Asteropsis 

 for this genus, but I venture to think this has been done without due acquaintance with 

 either the literature or the merits of the case. The remarks which I have made on the 

 genus Gymnasteria will be sufficient to indicate the history of the question, as well as the 

 justice of maintaining Porania and Asteropsis as independent genera. 



' l Mem. Soc. Plnjs. et Hist. Nat. Geneve, 1885, t. sxix. No. 4, p. 68. 



