REPORT ON THE ASTEROIDEA. 209 



are about ten or eleven in number, and decrease in size adorally and aborally. Of the 

 mouth-spines proper, situated on the free margin of the plates, the innermost three on 

 each side of the suture-line are long, robust, cylindrical, obtusely rounded, and form, 

 together with the corresponding spines of the companion plate, the comb which stretches 

 horizontally over the mouth-aperture. On the remaining portion of the free margin are 

 three or four small, equal-sized, cylindrical spines. The first adambulacral plate next to the 

 mouth-plate is narrow, with a biserial armature, consisting of about eight small, compressed, 

 slightly flaring, and truncate spines in each row. 



The madreporiform body is transversely oval in form, and not more than its own 

 breadth distant from the marginal plates. 



The terminal plate is large and broad, very deeply channelled anteriorly, and with two 

 or three short robust spinelets, which curve slightly over the furrow. 



Colour in alcohol, very light ochre-brown, almost verging towards grey. 



Locality. — Station 75. Between the islands of Fayal and San Jorge (Azores). 

 July 2, 1873. Lat. 38° 38' 0" N., long. 28° 28' 30" W. Depth 450 fathoms. Volcanic 

 mud. Surface temperature 70°'0 Fahr. 



Remarks. — This species is characterised by the single short, compressed, lateral spine, 

 with two closely placed small companions, by the broad and flaring spinelets on the actinal 

 surface of the adambulacral plates, and by the absence of an aboral line of spinelets on 

 the infero-marginal plates. The form is very nearly allied to Astropecten irregularis, 

 Linck, but is distinguishable by many points of detail when examples of the two species 

 are compared side by side. 



9. Astropecten irregularis, Linck. 



Astropecten irregularis, Linck, 1733, De Stollis marinis, p. 27, tab. vi. fig. 13. 



Asterias aranciaca, 0. F. Muller, 1776, Zool. Dan. Prod., p. 234, No. 2831. 



Astropecten Miilleri, Muller and Troschel, 1844, Archiv f. Naturgesch., Jahrg. x., Bd. i. p. 181. 



Astropecten echinulata, Muller and Troschel, 1844, Archivf. Naturgescb., Jahrg. x., Bd. i. p. 181. 



Localities. — " Porcupine " Expedition : 



Station 18. Off the west coast of Ireland, north-west of Achill Head. Lat. 54° 15' N., 

 long. 11° 9' W. Depth 183 fathoms. Bottom temperature 9°7 C. ; surface temperature 

 ll°-8 C. 



Station 46. Between Scotland and the Faeroe banks. Lat. 59° 23' N., long. 7° 4' W. 

 Depth 374 fathoms. Bottom temperature 7°'7 C. ; surface temperature 12°'l C. 



Station 67- East of the Shetland Islands. Lat. 60° 32' N., long. 0° 29' W. Depth 

 64 fathoms. Bottom temperature 9°-5 C. ; surface temperature ll°-0 C. 



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

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



Remarks. — These are all small forms and have a certain facies of their own, but they 



(zool. chall. exp. — PART LI. — 1888.) 27 



