REPORT ON THE RADIOLARIA. 1757 



2. Cdclostylus jlaheUatus, n. sp. 



Shell-mantle one and a half times as long as broad, very similar to that of the preceding species. 

 It differs from this mainly in the peculiar form of the twenty-four terminal coronets, which are 

 flabellate and very similar to the terminal branches of Ccelodcndrum Jlabdlatum (PL 121, figs. 5, 6). 

 I formerly supposed, therefore, that both forms belonged to one and the same species. But though I 

 had no complete specimens of the two si^ecies, I was afterwards led to the opinion that one and 

 the same peculiar form of terminal branches is here produced by adaptation to similar conditions in 

 two very different genera. Each coronet is a Hat flabellum, placed in a meridian plane, and 

 composed of eight paii's of spinulate branches as figured, loc. cit., in figs. 5 and 6. The cap-shaped 

 distal end of each finger is armed with eight to twelve recurved teeth. 



Divumsions. — Length of the shell 3"8, breadth 2"6. 



Habitat. — North Pacific, Station 252, surface. 



Genus 738. Cceloplegma^ n. gen. 



Definition. — C oe 1 o g r a p li i tl a with an odd frenulum on each galea and an 

 outer lattice-mantle, armed with fourteen styles (one odd and six paired styles on each 

 valve). 



The genus Cceloplegma, distinguished by the possession of fourteen coronal styles, 

 is closely allied to Coslodecas, but differs from it in the development of a new pair of 

 styles on each valve. These are placed between the odd nasal and the paired frontal 

 styles, are directed forwards, and may therefore be called pectoral styles, corresponding 

 to those of Calostylus. 



1. Cceloplegma murrayanum, n. sp. (PI. 127, fig. 1). 



Shell-mantle about as long as broad, its frontal perimeter subcircular, or slightly pentagonal, 

 with five convex sides, its sagittal perimeter also nearly circular. Odd nasal style with six to eight, 

 the paired pectoral styles with two or three, lateral styles with three to five, and tergal styles 

 with six to nine pairs of branches. The central capsule constantly contains masses of crystals 

 (figs. 4-7). Terminal coronets (on the free distal ends of the styles) three times furcate, each 

 with eight simple and short fingers. This interesting species, discovered by Dr. John Murray 

 in August 1882, during the expedition of H.M.S. " Triton," in great numbers in the Gulf Stream, 

 off the Ficroe Channel, is very variable and connected by numerous transitional forms with the 

 following closely allied species. (Compare the following note.) 



Dimensions. — Length of the shell 1"6 to 2-2, breadth I'o to 21. 



Hahitat. — North Atlantic, Gulf Stream, off the Freroe Channel, in depths between 40 and 200 



fathoms, John Murray. 



' Ccel(yplegma = 'S.o\\o\i framework ; xoi^oj, ■s'hiyfia,. 



