REPORT ON THE ASTEROIDEA. ir 
Chorology of the Genus Craspidaster. 
a. Geographical distribution :— 
Pactiric and HasTERN ARCHIPELAGO: One species between the parallels of 0° and 
40° N. 
Craspidaster hesperus off Japan and China, and in the Eastern 
Archipelago. 
8. Bathymetrical range: Appears to be confined to the Littoral zone: 20 fathoms is 
the greatest depth recorded. 
y. Nature of the Sea-bottom : Mud. 
Chorological Synopsis of the Species. 
Ocean. Range in Fathoms. Nature of the Sea-bottom. | 
| 
é Pacific and | 
Craspidaster hesperus . | Taster) Arahipolare, \ 20 Mud. | 
1. Craspidaster hesperus, Miller and Troschel, sp. (Pl. XVII. figs. 5-7; Pl. XVIII. 
figs. 1-4). 
Archaster hesperus, Miiller and Troschel, 1840, Monatsber. d. k. Akad. d. Wiss. Berlin, p. 104; System 
der Asteriden, 1842, p. 65. 
Stellaster sulcatus, Mobius, 1859, Neue Seesterne des Hamburger und Kieler Museums, p. 11, Taf. iv. 
figs. 1 and 2 (Abhandl. a.d. Gebiete Naturw. hrsg. v. d. naturwiss, Verein, Hamburg, Bd. iv. 
Abth. 2, 1860). 
Rays five. R=53 + mm. (the terminal plate being broken off in all the rays of the 
largest specimen); r=15 mm. Breadth of the ray across the second supero-marginal 
plates, 14°5 mm. 
General form depressed and rigid. Rays moderately long and flat, tapering from the 
base to the extremity, which is not attenuated or sharply pointed. Interbrachial ares 
wide and well rounded. Abactinal surface plane. Actinal surface plane. Margin well 
rounded ; lateral walls highest in the interbrachial arc, decreasing gradually towards the 
end of the ray. 
The abactinal surface of the disk and rays is covered with paxille of a rather peculiar 
form, which I have not observed in any other species. In the immediate centre of the 
disk the paxille are small, crowded, and individually indistinguishable ; they also 
diminish greatly in size as they proceed along the ray, but remain perfectly distinct, and 
though closely placed throughout, in no way interfere with one another’s form by crowd- 
(ZOOL, CHALL. EXP.—PART LI.—1887.) , 23 
