C38 THE VOYAGE OF H.M.S. CHALLENGER. 



saccular, membranous sheath, upon which are a few isolated and comparatively large 

 pedicellaria?. 



The madreporiform body is rather small and elongately oval, slightly convex, and 

 with the surrounding parts somewhat prominent ; the surface is traversed with tolerably 

 numerous, slightly convoluted, striation - furrows, the main direction of which corre- 

 sponds to the major diameter. A very distinct anal aperture is present in an excentric 

 position, and within its periphery the termination of a punctured (?) tube may be 

 seen. 



Colour in alcohol, a bleached ashy yellowish white. 



Locality. — Station 181. In the Coral Sea, south-east of New Guinea. August 25, 

 1874. Lat. 13° 50' 0" S., long. 151° 49'0"E. Depth 2440 fathoms. Red clay. Bottom 

 temperature 35° - 8 Fahr. ; surface temperature 80 o- Fahr. 



Remarks. — This species is perhaps the most handsome member of the group. It is 

 distinguished from all other forms by the long delicate lateral spines, by the peculiar 

 aborted character of the mouth-spines, by the rudimentary nature of the abactinal plating, 

 as well as by a number of minor details which it is unnecessary to recapitulate. 



8. Freyella titberculata, n. sp. (PL CXVII. figs. 1-3). 



Rays six. R = 240 mm. ; r = 6 mm. R = 40 r. Breadth of a ray at the base 4 mm. ; 

 at the widest part of the ovarial inflation, 5 mm. (measured at 15 mm. from the disk) ; 

 and at 80 mm. beyond the disk, 2"60 mm. 



Rays of great length and delicacy, cylindrical at the base, gradually swelling at a 

 short distance from the disk into a very slightly fusiform ovarial inflation, which as gradually 

 contracts, and the ray thence becomes subtriangular and tapers continuously to a very 

 attenuate extremity. The ovarial region extends for about 30 mm. from the disk, i.e. 

 about the proximal eighth of the ray. The rays have a well-spaced appearance at the 

 base, for this genus, and the interbrachial arc is sharply rounded. 



The disk is small and its abactinal surface is flush with that of the rays at the base ; 

 it was probably capable of slight inflation, but there is in its present state a faint depres- 

 sion within the periphery of the perisomatic ring. The abactinal area of the disk and 

 of the rays, even for some distance beyond the ovarial inflation, is covered with small 

 hexagonal plates, overlaid with the most delicate membrane. On the ovarial region the 

 plates are larger than elsewhere and their major diameter lies parallel to the axis of 

 the ray. Each plate bears centrally a small rounded tubercle, on which is articulated 

 a short, delicate, tapering, and sharply pointed spinelet, about l - 25 mm. in length on 

 the disk; these are encased in a very delicate membranous sheath, upon which are 

 crowded minute pedicellarise. A number of the spinelets on the disk and nearly all those 

 on the ovarial regions are now devoid of membrane, probably accidentally on account of 



