260 THE VOYAGE OF H.M.S. CHALLENGER. 
most part of the ray may bear a single pedicellaria, but along the ray they are either naked 
or bear only small cilia-hke, but invested, spinelets. 
The madreporiform body is hidden by paxillee. 
Colour in alcohol, a bleached ashy or yellowish white. 
Young Phase.—A small example was obtained at Station 188 in company with a 
larger specimen, which seems to me in every way identical with the type form. About the 
small example, however, which has a radial measurement of 18 mm., I feel much doubt as 
to whether it belongs to this species or to a new one. The actinal characters conform 
closely enough with those of Luidia forficifer, but on the abactinal surface the paxille 
are furnished with a robust central papilliform granule or incipient spinelet, of which no 
trace is found in the adult forms above described. Without more material to furnish a 
clue as to the intermediate stages (if such really exist), I am unable to express a definite 
opinion on the young example under notice. ; 
Localities.—Station 187. Booby Island, Torres Strait. September 9, 1874. Liat. 
10° 36’ 0” S., long. 141° 55’ 0” E. Depth 6 fathoms. Coral mud. Surface tempera- 
ture 77°°7 Fahr. 
Station 188. In the Arafura Sea, near the entrance to Torres Strait. September 10, 
1874. — Lat. 9° 59’ 0” S., long. 139° 42’0” E. Depth 28 fathoms. Green mud. Surface 
temperature 78°°5 Fahr. 
Remarks.—This species may be distinguished by the form of the rays, by the 
character of the paxilla, and by the armature of the adambulacral and infero-marginal 
plates. 
Family PENTAGONASTERIDA, Perrier, 1884. 
The family Goniasteridze, as defined by M. Perrier’ in 1875, has been recently divided 
by him* into four families, the Pentagonasteridew, Pentacerotide, Antheneide, and Gym- 
nasteriide. With this step I entirely concur, reserving only some doubt about the validity 
of the Antheneidz as a group worthy of family rank, its credentials appearing to me to be 
more or less artificial. 
The limits of the genera included in the Pentagonasteride have been critically and 
justly discussed by Perrier.’ I have, however, ventured to differ from him in that I have 
limited the term Astrogoniwm to those species for which he has proposed to restore the 
generic name of Stephanaster.* The reasons for this step, which seems to me unavoidable, 
are discussed on p. 285. I have furthermore felt obliged to separate a small group of 
species distinguished by definite structural characters from the other Pentagonasteride, for 
1 Révis. Stell. Mus., p. 25 (Archives de Zool. expér., 1875, t. iv. p. 289). 
* Nouv. Archives Mus. Hist. Nat., 2e Série, 1884, t. vi. p. 165. 
3 Révis. Stell. Mus., p. 100, ef seg. (Archives de Zool. expér., 1876, t. v., p. 6, et seq.) 
* Comptes rendus, 1885, t. ci. p. 885; Ann. Sci. Nat. (Zool.), 1885, t. xix., Art. No. 8, p. 30. 
