170 THE VOYAGE OF H.M.S. CHALLENGER. 
a number of spiniform granules, which are most robust and elongate on the adoral half 
of the plate. Beyond this, these appendages do not appear to present any special 
arrangement or to form definite series, and they impart a very echinulate aspect to the 
mouth-angles. 
The actinal interradial areas, which are large, are covered with membrane and minute 
subspiniform, conical granules. These are small, numerous, rather closely placed, and 
distributed over the whole area; here and there a faint appearance of grouping may be 
observed, which seems to suggest the indication of the actinal intermediate plates. Of 
the actual outline, arrangement, or character of these plates no observations can be made, 
owing to the uniform and thick covering of membrane with which they are overlaid. 
Colour in alcohol, yellowish white, the paxillar area having a rather browner shade. 
Locality.—Station 89. Off the west coast of Africa, between the Canary Islands and 
the Cape Verde Islands. July 23,1873. Lat. 22°18’ 0” N., long. 22° 2/0” W. Depth 
2400 fathoms. Globigerina ooze. Bottom temperature 36°°6 Fahr.; surface temperature 
73°°5 Fahr. 
Remarks.—I know of no other starfish with which this remarkable and elegant form 
can be confounded, 
Subfamily Crenopiscrin#, Sladen, 1886. 
Genus Ctenodiscus, Miiller and Troschel. 
Ctenodiscus, Miiller and Troschel, System der Asteriden, 1842, p. 76. 
Anodiscus (? Valenciennes, M.S.), Perrier, Ann. Sci. Nat., 1869, 5e Sér., t. xii. p. 298. 
I have on a preceding page (p. 125) stated my reasons for associating this genus 
with the Porcellanasteride, and I have also remarked on the presence of an extremely 
minute pore at the extremity of the epiproctal cone, which is more or less prominently 
developed in the centre of the abactinal area. 
Chorology of the Genus Ctenodiscus. 
a. Geographical distribution :— 
Artantic : Two species :—one between the parallels of 60° and 80° N., the 
other between the parallels of 30° and 60° 8. 
Ctenodiscus corniculatus off the Scandinavian and North 
American coasts, off Greenland, Spitzbergen, and Nova Zembla, 
and in the Kara Sea. Ctenodiscus australis off the eastern coast 
of the southern point of America. 
Paciric: One species between the parallels of 40° and 60° 8S. 
Ctenodiscus procurator off the western coast of the southern 
point of America. 
