REPORT ON THE ASTEROIDEA. 463 
Anal aperture large, subcentral, surrounded by five or six subtubercular papilla. 
Ambulacral tube-feet, which are arranged in two rows, have a large, flat, fleshy 
terminal disk. 
No pedicellarize of any kind are present. 
Remarks.—The character of the abactinal and actinal plating, the remarkable fasci- 
culated spinulation of the abactinal plates, and the character of the armature of the 
adambulacral plates, together with the absence of papule on the abactinal surface, at once 
distinguish Korethraster from all other genera at present known. The morphological 
structure of the form has led Drs Danielssen and Koren’ to place Korethraster in a 
distinct family, which they established for its reception (Korethrasteride), but although I 
do not feel prepared to oppose that course, I hesitate for the present about following it, 
and until more is known of the anatomy of this and allied forms, I prefer to leave the 
genus in the family Solasteride, as classified by Perrier, placing it, however, in a sub- 
family. 
Several starfishes dredged during the ‘“ Blake” Expedition have been referred by 
Perrier to this genus, and were originally desecribed* as representing two distinct species 
under the names of Korethraster palmatus and Korethraster radians; the latter was 
subsequently placed, however, by its author under the name of Korethraster hispidus, 
but so far as I can judge from the description given, and no figure, I am inclined to think 
that this is certainly not the same as Wyville Thomson’s Korethraster hispidus; and I 
feel very great doubt indeed as to whether either of the forms belong to the genus Kore- 
thraster at all. For the same reason, owing to insufficient description, I am reluctantly 
compelled to place a third form, described by Perrier* under the name of Korethraster 
setosus, in the same category of uncertainty. On these grounds | have not included the 
forms mentioned in my consideration of the chorology of the genus Korethraster given 
below. 
Chorology of the Genus Korethraster. 
a. Geographical distribution :— 
AtLantic: One species between the parallels of 60° and 80° N. 
Korethraster hispidus, in the Faerée Channel, off the coast of Nor- 
way, and south of Franz-Josef Land. 
Den Norske Nordhavs-Expedition, 1876-1878, Zoologi, xi. Asteroidea, 1884, p. 99. 
Bull. Mus. Comp. Zool. Harvard, 1881, vol. ix. No. 1, p. 12. 
Nouv. Archives Mus. Hist. Nat., 1884, 2e Série, t. vi. p. 212.” 
Rapport sur les Travaux de la Commission chargée par M. le Ministre de I’'Instruction publique d’etudier 
la Faune sous-marine dans les grandes profondeurs de la Méditerranée et de ’Océan Atlantique, par M. Alphonse 
Milne-Edwards, Membre de l'Institut (Extrait des Archives des Missions scientifiques et littératres. Troisitme 
série, Tome neuvitme. Paris: 1882), p. 51. 
me © Be 
