606 THE VOYAGE OF H.M.S. CHALLENGES. 



buccal membrane, being parallel to the median interradial line, the outer one radiating 

 outward at an angle of about 45° in the same plane. These spinelets are covered with 

 delicate membrane, upon which a few microscopic pedicellarise are borne near the tip. 

 Midway on the actinal surface of the plate is a single, small, tapering, secondary or super- 

 ficial spinelet, about 175 mm. in length, also invested with membrane bearing pedicel- 

 larise. At the aboral end of each plate is a single small invested spinelet, directed hori- 

 zontally over the ambulacral furrow, and separating the first and second tube-feet. It is 

 similar in character and size to the small inner spinelet on the adambulacral plates above 

 described. 



The madreporiform body, which is small and subtubercular, is situated close to the 

 margin of the disk, and it is marked with very few and simple striation furrows. 



Colour in alcohol, a bleached ashy grey, with a slight brownish or flesh-coloured shade 

 on the ovarial regions owing to the transparency of the membrane allowing the internal 

 organs to be distinctly visible. 



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

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

 Bottom temperature 37°"2 Fahr. ; surface temperature 40 o- Fahr. 



Remarks. — This species, although allied to Brisinga endecacnemos and Brisinga 

 armillata in many points of general detail, is readily distinguished from the former by the 

 smaller number of rays, by their great delicacy, as well as by the delicacy of all their 

 appendages, by the small and limited ovarial inflation, by the great prominence of the 

 transverse ridges over these regions, by the absence of tegumeutary spicules, and by the 

 armature of the adambulacral plates and mouth-plates. 



Brisinga verticillata may also be distinguished from Brisinga armillata by the 

 number of rays, by their great delicacy, by the character of the ovarial regions, and by 

 the great prominence of the transverse calcareous ridges. The general habit of the two 

 species is quite different. 



4. Brisinga cricophora, n. sp. (PI. CIX. figs. 6-8). 



Rays eleven. R = ? ; r = 10 mm. Breadth of a ray at the base, 6 - 25 mm. ; at the 

 widest part of the ovarial inflation, 7 mm. (measured at 25 mm. from the disk) ; at 120 

 mm. from the disk, 5 mm. 



Rays very long and narrow, cylindrical, and slightly depressed at the base, gradually 

 swelling into a very elongate, slightly fusiform ovarial inflation, which contracts still more 

 gradually and terminates imperceptibly, being altogether lost at 75 mm. from the disk. 

 Beyond this the section of the ray is subtriangular, with a broad truncate median 

 carination ; the rays are rather broad and depressed, much more so than in Brisinga 

 endecacnemos. 



