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



Localities. — Station 46. Off the coast of North America, east of New Jersey. May 6, 

 1873. Lat. 40 c 17' 0" N, long. 66° 48' 0" \V. Depth 1350 fathoms. Blue mud. 

 Bottom temperature 37°"2 Fahr. ; surface temperature 40° "0 Fahr. 



Station 47. Off the coast of North America, east of Massachusetts. May 7, 1873. 

 Lat. 41° 14' 0" N, long. 65° 45' 0" W. Depth 1340 fathoms. Blue mud. Surface 

 temperature 42° - 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. 



Remarks. — Freyella bracteata is distinguished by the number of its rays, by their 

 comparative rigidity, by the proportionally short and robust lateral spines, by the char- 

 acter and the small number of the spinelets on the abactinal plates, and by the character 

 of the armature of the mouth-plates. 



6. Freyella dimorpha, n. sp. (PI. CXV. figs. 1-5). 



Rays twelve. R = 250 mm. ; r= 10 mm. R = 25 r. Breadth of a ray at the base, 

 47 mm. ; at the widest part of the ovarial inflation, 8 to 9 mm. (measured at about 16 

 mm. from the disk) ; at 50 mm. from the disk the breadth is 3 -25 mm. ; and at about 

 midway between the extremities, 2 '5 mm. 



Bays very long and delicate, narrow and cylindrical at the base, and immediately 

 swelling gradually into an elongately oval or subfusiform ovarial inflation, the tumidity 

 of which is not great, and is of nearly the same dimension for some distance along the 

 median part of the region; it contracts gradually outwardly and terminates at about 30 

 to 32 mm. from the disk, thus occupying about the proximal eighth of the length. 

 Beyond the ovarial region, the ray is subtriangular, with a truncate median carination, 

 and tapers gradually to the extremity. The interbrachial arcs are simple clefts. 



The disk is small, with the abactinal surface subplane and probably capable of slight 

 inflation ; it is on a higher level than the abactinal surface of the rays, and the margin is 

 sharply rounded and passes towards the basal part of the rays almost precipitously. The 

 abactinal surface of the disk and of the rays as far as the ovarial region extends is covered 

 with imbricating, subhexagonal plates, overlaid with a delicate membranous tissue. The 

 plates are thin, but often comparatively large, and their greater diameter lies transverse 

 to the direction of the ray. Each plate bears from five to ten (usually about half a 

 dozen) very minute spinelets, from 0*35 to - 45 mm. in length, covered with simple 

 membrane and articulated on small miliary tubercles. The spinelets have a tendency to 

 form lineal series along the major, transverse, diameter of the plates, especially on the 

 lateral regions. Isolated sessile pedicellarise are to be found here and there upon the 

 plates, though in some examples they appear to be wanting altogether. The disk has a 



