284 Mr. H. J. Carter on 



Bivalvata. In all the spicule is of the same form, viz. acerate, 

 smooth, curved, fusiform, and sharp-pointed, but for the most 

 part very small and often minute, i. e. not exceeding 7-6000ths 

 in. in length, with almost immeasurable thinness, combined 

 with great thickness of keratine in the fibre, which, as before 

 stated, leads to great toughness and resiliency. In my British 

 specimens of Chalind polychotoma, obtained from the English 

 Channel opposite this place (Budleigh-Salterton), the spicule 

 is about 30 by 2^-6000ths inch in its greatest dimensions. 



Fam. 1. Chalinida. 

 " Char. Digitations solid, vertical or procumbent." 



Group 1. DiGITATA. 



Chalina polychoiomaj Esper. 



Of this species in Mr. Wilson's collection there are several 

 specimens, whose characters having already been mentioned, 

 need not be repeated here. Largest specimen 2 feet long. 

 Depth not mentioned. Neither the colour when fresh nor the 

 depth of the dried specimens is stated. 



Ghalina polychotoma^ var. trichotoma. 



Described in the 'Annals^ for 1885 (vol. xv. p. 115). 

 This variety only differs from the foregoing in most of the 

 ends of the branches being more or less expanded and triclio- 

 tomously divided. 19 inches long. Presented to the British 

 Museum in the name of J. Bracebridge Wilson, Esq., M.A., 

 F.L.S. Dried specimen. 



Ghalina poJychotomay var. compressa. 



Where the stem becomes more or less expanded and com- 

 pressed at the commencement of the branches^ or where the 

 latter becomes expanded towards their ends spatuliform [spa- 

 tulata). Vents scattered over the expanded portions, chiefly 

 on one side, comparatively small and not projected. Two 

 wet specimens : — viz. 1, wholly compressed ; colour, when 

 fresh, "purple-slate;" 5| in. long. 2, subcompressed ; 

 colour, when fresh, " pale buff-brown ;" 13 in. long. Depth 

 of both 19 fath. 



Ghalina poly chotoma^ var. oculata. 



Stems thick, more or less irregular in form, i. e. more or 

 less irregularly expanded and united together in their whole 

 length, flabelliforra, proliferous. Colour dark-brown reddish. 



