REPORT ON THE ASTEROIDEA. 421 



situated between the dorso-central plate and a basal plate, standing in the right posterior 

 interradiura when the madreporiform body is placed in the right anterior interradium. 



localities. — Station 46. Off the coast of North America, east of New Jersey and 

 Long Island. May 6, 1873. Lat. 40° 17' 0" N. ; long. 66° 48' 0" W. Depth 1350 

 fathoms. Blue mud. Bottom temperature 40 o- Fahr. 



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. 



Station 120. Off Pernambuco. September 9, 1873. Lat. 8° 37' 0" S., long. 34° 28' 

 0" W. Depth 675 fathoms. Red mud. Surface temperature 78°-0 Fahr. 



" Porcupine " Expedition : 



Station 87, 1869. 1 North-west of the Hebrides. Lat. 59° 35' N, long. 9° 11' W. 

 Depth 767 fathoms. Bottom temperature 5 C, 2 C. ; surface temperature 11 Q, 4 C. 



" Triton " Expedition : 



Station 11. In the Faeroe Channel. August 28, 1882. Lat. 59° 29' N., long. V 13' 

 W. Depth 555 fathoms. Bottom temperature 45°'5 Fahr. 



Station 13. In the Faeroe Channel. August 31, 1882. Lat. 59° 51' 2" N, long. 

 8' 18' 0" W. Depth 570 fathoms. Bottom temperature 45°7 Fahr. 



2. Zoroaster tenuis, n. sp. (PI. LXVII. figs. 1 and 2 ; PI. LXVIII. figs. 7 and 8). 



Rays five. R = 15*5 mm. ; r = 2'5 mm. R = 6"2 r. Breadth of a ray near the base, 

 3 mm. 



Rays elongate, delicate, tapering from the base to the extremity, roundly carinate 

 abactinally. Disk convex and high abactinally. Interbrachial arcs acute. 



The centre of the disk is occupied by a large dorso-central plate, which is elevated 

 centrally into a large, broad-based, conical eminence. This is surrounded by five small 

 subquadrate under-basal plates ; and then follow five large irregularly subpentagonal 

 basal plates with festooned margins : the latter series do not fit close up to the under- 

 basals, but are separated by a small membranous space from them and the free portions 

 of the dorso-central plate. The succeeding primary radial plates, which also have fes- 

 tooned margins, pass far between the basal plates towards the under-basal plates, but are 

 separated from them by a space about equal to the length of the latter, in which perhaps 

 a small intermediate plate may be present, but I am uuable to say definitely without 

 injuring the specimen. The succeeding median radial plates are large and occupy nearly 

 the whole of the breadth of the ray, being separated from the marginal plates by only a 

 series of very small plates, which does not extend to the extremity. Single isolated papula? 

 occur on each side of these small plates. The plates of the median radial series are 

 strongly bent and each bears on the centre of the keel a comparatively large robust 



1 This Station is recorded in "The Depths of the Sea," but I have not seen any specimens from it. 



