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



great number of small spiracula not quite so closely placed as those ou the disk, and not 

 arranged in lines. 



The ambulacral furrows are rather widely petaloid. and rapidly constricted at the 

 extremity. The armature of the adambulacral plates consists of three short spines, nearly 

 uniform in length, pointed, and covered with a membrane expanded into a lanceolate 

 sbape, but with no terminal saccular prolongation. Each series of spines is placed diago- 

 nally upon its plate, or oblique to the line of the furrow. The aperture-papillae are large 

 and broadly subspatulate or even subrhomboid, expanded somewhat obliquely, the pedicle 

 seeming to be attached rather on one side. The mouth-plates are rather broad, prominent 

 aborally, and have five or six short mouth-spines attached to the lateral aliform extensions, 

 and directed horizontally. Two short, robust, subcorneal secondary mouth-spines are borne 

 on the superficies of each plate — one near the adoral extremity, and the other, wiiich is 

 thickest, placed midway between this spine and the aboral extremity of the mouth- 

 plate. 



The actino-lateral spines are long and well spaced, about forty on each side of a furrow, 

 the eleventh or twelfth from the mouth being longest. The spines within the disk do not 

 quite meet in the median interradial line, and those along the outer third of the ray 

 diminish in length very rapidly ; they are, however, rather irregular in their length 

 throughout, which gives a ragged appearance to the fringe. The spines are pointed at 

 their extremities, and the web is very slightly indented between. 



Colour in alcohol, yellowish grey. 



Locality. — Station 158. South of Australia, 1099 miles south-west of Cape^ Otway. 

 March 7, 1874. Lat. 50° 1' 0" S., long. 123° 4' 0" E. Depth 1800 fathoms. Globigerina 

 ooze. Bottom temperature 33°"5 Fahr. ; surface temperature 45°'0 Fahr. 



Remarks. — Hymenaster crucifer is distinguished, as its name implies, by the peculiar 

 cross-like markings formed by the paxillae-crowns. A further characteristic feature is 

 furnished by the general structure of the supradorsal membrane and the lineal disposition 

 of the spiracula. 



13. Hymenaster anomalus, Sladen (PI. LXXXIX. figs. 3 and 4 ; PI. XCI. figs. 4-6). 



Hymenaster anomalus, Sladen, 1882, Journ. Lina Soc. Lond. (Zool.), voL xvi. p. 228. 



Marginal contour stellato-pentagonal. Iuterbrachial arcs wide and rather sharply 

 and angularly indented, the minor radius being in the proportion of 63 to 65 per cent. 

 R= 15 mm. ; ?'=9'5 mm., approximately. Pays subtriaugular in outline, and tapering 

 to a fine extremity. Form very depressed, only slightly elevated in the centre of the 

 disk. Marginal fringe quite inconspicuous when seen from above. 



The supradorsal membrane is furnished with uniformly thick fibrous bands, closely 

 reticulated, the network exhibiting a certain incipient regularity of construction. The 



