REPORT ON THE ASTEROIDEA. 261 



which I propose the generic name of Gnathaster. I have also retained as genera several 

 of the sections relegated by Perrier to subgeneric rank under Pentagonaster, viz., Cal- 

 liaster, CaUiderma, Astrogonium, SteUaster, and Ogmaster (= Dorigona). Though the 

 characters upon which these genera are based exhibit many transitional stages, it appears 

 to me too sweeping a measure to merge them in one generic term. That the differences 

 should be slight and the cases of transition frequent in a large and widely distributed 

 family such as the Pentagonasteridae is not surprising. As, however, the morphological 

 characters of the forms in question are in my opinion sufficient to warrant recognition, it 

 seems to me that to lose the record of their significance by an unnecessary exercise of 

 comprehensiveness would be a mistake. 



Astrogonium and Dorigona, it should be mentioned, have recently been restored by 

 Perrier ' himself as generic names, but the sense in which they have been applied appears 

 to me to be inadmissible, for reasons which I shall give in detail. 



I have substituted the generic name Ogmaster for that of Dorigona. The starfish 

 described by Gray 2 in 1866 under the name of Dorigona reevesii is the same species as 

 that previously described by Midler and Troschel 3 in 1842 under the name of Goniodiscus 

 capella. In 1865 von Martens 4 placed this form in a subgenus to which he gave the 

 name Ogmaster, ranking it under Goniaster. The claim of this form to generic recogni- 

 tion has since been admitted, and it follows in my opinion that the name of the starfish in 

 question should therefore be Ogmaster capella (M. & T.), von Martens. (Its synonyma are 

 Dorigona reevesii, Gray, and Goniaster miilleri, Liitken ; but not Goniaster (SteUaster) 

 miilleri of. von Martens.) The Goniaster (SteUaster) miilleri of von Martens is a true 

 SteUaster, which is so nearly allied to SteUaster childreni that I am unable to distinguish 

 it, and I am therefore constrained to consider Goniaster miilleri as a synonym of that 

 species. Both Liitken and Perrier have been in error in regarding von Martens' form as 

 identical with the species described by Gray as Dorigona reevesii. 



A second form which has been referred to the genus Dorigona is the starfish described 

 by Mobius 5 under the name of Astrogonium longimanum. This form is totally distinct 

 from Gray's form, and merits, in my opinion, an independent generic recognition. I 

 therefore propose for it the name of Iconaster. It is characterised by the naked abactinal 

 plates margined by very remarkable valve-like plates, by the character of the adambulacral 



1 Ann. Sci. Nat. (Zool.), 1885, t. xix., Art. No. 8, p. 30. I would here take the opportunity of mentioning 

 that the sheets of this Report which treat of the Porcellanasteridse and Aichasteridae were printed off before 

 I had seen this last mentioned important memoir by Prof. Perrier, and I was consequently unable to refer to 

 the species described therein, as I otherwise should have done. 



2 Synop. Spec. Starfish Brit. Mus., London, 1866, p. 7, pi. 7, figs 3, 3a. 



3 System der Asteriden, 1842, p. 61. 



4 Ueb. Ostasiat. Echin., Archiv f. Naturg., Jahrg. xxxi., Bd. i. p. 359. 



5 Neue Seesterne des Hamburger und Kieler Museums, 1859, p. 7, i if. :.. 6g . •'>, 6. (Abhandl. a. </. 

 Gebietr Naluriv. hrsff. r. d. nalurwiss. Verein, Hamburg, Bd. iv. Abth. 2, 1860.) 



