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



slightly oblique. On the margin of the adambulacral furrow, at the base of the innermost 

 adambulacral spine, may be one or more small sessile, triangular, forficiform pedicellariae, 

 not larger than the forcipiform pedicellariae on the abactiual and lateral areas. 



There is a longitudinal series of plates immediately external to the adambulacral 

 plates, which bear a single spinelet a shade larger than those on the abactinal plates and 

 numerous forcipiform pedicellariae ; the spinelets form a regular longitudinal row along 

 the ray. At the base of the ray the innermost four or five spinelets may be longer than 

 any of the others. Separated from these plates (? the representatives of infero-marginals) 

 by a wide space occupied by numerous forcipiform pedicellariae, a second but much less 

 clearly defined longitudinal series of plates may be indistinctly traced, which are perhaps 

 the representatives of supero-marginal plates, but differ in no way either in superficial 

 character or armature from the abactinal plates generally, except that they sometimes 

 bear two spinelets side by side. 



The madreporiform body, which is large and placed near to the margin, is surrounded 

 by a circlet of spinelets. The striations upon its surface are rather coarse and not much 

 convoluted. 



Colour in alcohol, a bleached yellowish white. 



Locality.— Station 50. South of Halifax, Nova Scotia. May 21, 1873. Lat. 42° 8' 

 0" N., long. 63° 39' 0" W. Depth 1250 fathoms. Blue mud. Bottom temperature 38°-0 

 Fahr. ; surface temperature 45°'0 Fahr. 



Remarks. — Asterias (Hydrasterias) ophidion is distinguished by the six long worm- 

 like rays ; by the delicate, wide-meshed quadrate network of the abactinal area ; by the 

 few and isolated spinelets ; by the isolated pedicellariae ; and by the diplacanthid armature 

 of the adambulacral plates. 



E. Asterias mulleri group : Subgenus Leptastekias. 



15. Asterias (Leptasterias) mulleri, Sars, sp. 



Asteracanthion Mulleri, Sars, 1844, Archiv f. Naturgesch., Jahrg. x., Ed. i. p. 169; Fauna Litt. 



Norvegise, 1846, lste Hefte, p. 56, tab. 8, figs. 38, 39 ; Oversigt af Norges Echinodermer, 



Christiania, 1861, p. 88. 

 Asterias Miilleri, Norman, 1865, Ann. and Mag. Nat. Hist., ser. 3, vol. xv. p. 127. 

 Leptasterias Mulleri, Verrill, 1866, Proceed. Boston Soc. Nat. Hist., vol. x. p. 350. 



Localities. — " Porcupine " Expedition : 



Station 67. East of the Shetland Islands. Lat. 60° 32' 0" K, long. 0° 29' 0" W. 

 Depth 64 fathoms. Bottom temperature 9°"5 C. ; surface temperature ll o- C. 



Station 68. East of the Shetland Islands. Lat. 60° 23' 0" N., long. 0° 33' 0" E. 

 Depth 75 fathoms. Bottom temperature 6 0, 7 C. ; surface temperature ll° - 4 C. 



Station 82. In the Faeroe Channel. Lat. G0° 0' 0" N., long. 5° 13' 0" W. Depth 

 312 fathoms. Bottom temperature 5°'2 C. ; surface temperature 11°*2 C. 



