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



armature, and by the union of the supero-marginal plates throughout the ray. The 

 synonyms of Iconaster longimanus, Mobius, sp., are Astrogonium longimanum, Mobius, 

 Astrogonium souleyeti, Dujardin and Hupd, Goniaster longimanus, Ltitken, Pentagonaster 

 longimanus, Terrier, and Archaster lucifer, 1 Valenciennes. 



On the grounds above detailed I consider that the name Dorigona should be ranked as 

 obsolete. I am unable to express a definite opinion as to the position of several forms 

 recently referred to Dorigona, but I am inclined to think that some of them will perhaps 

 fall within the scope of the genus Nymphaster described on a succeeding page. 



I have added to this family four new genera discovered by the Challenger, and I have 

 also included the genus Nectria. which has latterly been relegated by Perrier 2 to the 

 Linckiidse. 



The interesting genus Anthenoides described by Perrier 3 is referred by him to this 

 family. 



In concluding these notes I would remark tbat Perrier 4 in his latest work has ao-ain 

 reverted to the family name of Goniasteridse. I think this unfortunate, and in fact inad- 

 missible, unless M. Perrier has relinquished the amended classification of the genera 

 included in that group, proposed by him in 1884, and noticed above. The scope and 

 significance of the family Goniasteridse ( Verrill), Perrier, 1875, is quite different from that 

 of the family Pentagonasteridse, Perrier, 1884. The latter I have adopted in the present 

 work, and consider that it ought to be maintained. 



Synopsis of the Genera included in the Family Pentauonasterid.t. 



A. Abactinal area with rounded, polygonal, or paxilliform plates. Granules or 



spinelets when present co-ordinated ...... Pentagonasterin.e. 



a. Abactinal area covered with rounded or polygonal plates ; sometimes 

 subtabulate, and either smooth or bearing granules, but not 

 forming true paxillae. 

 a. Supero-marginal plates separated throughout the length of ths 

 ray by abactinal plates. Abactinal plates not margined by 

 elongate valvular plates. 

 a. Actinal intermediate plates and infero-marginal platea 

 smooth or granulose ; devoid of prominent spinelets. 

 i. Marginal plates smooth or granulose. 



1 In citing this erroneous reference to Archaster in the list of species given on p. 122 supra (line 21), I have 

 inadvertently written Dorigona longimana, Mobius, sp., instead of Iconaster longimanus, Mobius, sp. The 

 reader will please make the necessary correction. The sheet was unfortunately printed off before the error was 

 noticed. 



2 Nouv. Archives Mus. Hist. Nat., 2e Sdrie, 1878, t. i. p. 79. (On p. 19 of the same work Nectria is 

 ranked in the Goniasteridae.) 



3 Bull. Mus. Comp. ZooL, Harvard, 1881, vol. ix., No. 1, p. 23; Nouv. Archives Mus. Hist. Nat., 2e Sene, 

 1884, t. vi. p. 246. 



4 Ann. Sci. Nat. (Zool.), 1885, t. xix., Art. No. 8, p. 30. 



