REPORT ON THE ASTEROIDEA. 475 



papilla is comparatively large, and free on its aboral side only, forming a regular semi- 

 circular lip, the remainder of the papilla beiug entirely hidden in membrane. 



The mouth-plates are short, but widely expanded laterally, rising by a gradual slope 

 into a high and angular median keel, which forms a prominent peak aborally. Each 

 plate bears one moderately robust secondary or superficial spine placed rather nearer the 

 anterior margin of the plate than the middle. These spines are shorter than the mouth- 

 spines proper, and are covered with a thick investiug-membrane slightly sacculate at the 

 extremity. Five mouth-spines are situated on the horizontal margin of each plate, the 

 innermost the longest, the next slightly smaller, and the outer three much smaller. Each 

 of the spines is covered with a moderately thick subsacculate investing membrane ; and 

 no web is developed, except in a single abnormal instance, where a secondary spine is 

 united with the inner or first mouth-spine proper. 



The first or most adoral transverse combs of the adambulacral plates of two neigh- 

 bouring rays touch one another at their bases behind the aboral peak of the mouth-plates, 

 but are not joined together. 



The actino-lateral spines are long, delicate, closely placed, and extend to the margin 

 of the actinal surface ; the web is faintly rounded over their extremities and slightly 

 festooned between. The spines are horizontal in their disposition, forming a flat actinal 

 surface to the disk ; the fringe extends very slightly beyond the margin ; and the spines 

 diminish to quite microscopic proportions at the extremities of the ray. 



Colour in alcohol, a general pinkish white on the abactinal area, verging on flesh 

 colour. The actino-lateral spines, the spines of the adambulacral armature, the mouth- 

 plates, and the mouth-spines, are all of a delicate rosy pink colour ; and this, seen through 

 the semitransparent light flesh-coloured investing tissue, gives an exquisitely beautiful 

 appearance to the underside of the starfish. 



Locality. — Station 311. Off the entrance to Smyth Channel. January 11, 1876. 

 Lat. 52° 45' 30" S., long. 73° 46' 0" W. Depth 245 fathoms. Blue mud. Bottom 

 temperature 46°'0 Fahr. ; surface temperature 50°"0 Fahr. 



Remarks. — This remarkably handsome species is distinguished from all other forms by 

 the regular stellate character of the paxillse-crowns, by the armature of the adambulacral 

 plates, and by the general character of the actinal surface. 



5. Pteraster semireticulatics, Sladen (PI. LXXV. figs. 5 and 6 ; PI. LXXVII. figs. 

 5 and 6). 

 Pteraster semireticulatus, Sladen, 1882, Journ. Linn. Soc. Lond. (Zool.), vol. svi. p. 195. 

 Marginal contour substellate ; interbrachial arcs well indented, the minor radial pro- 

 portion being 57 per cent. R= 14 mm. ; r = 8 mm. The sides of the rays slightly and 

 gracefully curve outward, and the tips are naturally upturned and incised, bringing the 

 extremity of the ambulacral furrow upon the abactinal area. Abactinal profile rather high 



