REPORT ON THE RADIOLARIA. 1313 



The genus Cryptocapsa differs from the preceding Dicolocapsa, its ancestral form, 

 in the peculiar shape of the cephalis, which is nearly perfectly enclosed in the upper part 

 of the inflated thorax. It has, therefore, to the latter the same relation as Carpocanium 

 bears to Anthocyrtis. 



1. Cryptocapsa bacca, n. sp. 



Cephalis spherical, with small circular pores enclosed in the upper part of the thorax, which is 

 ovate, smooth, and exhibits regular, circular pores, about as broad as the bars. 

 Dimensions. Cephalis 0'03 diameter, thorax 0'15 long, 0'12 broad. 

 Habitat. Central Pacific, Station 265, depth 2900 fathoms. 



2. Cryptocapsa pila, n. sp. 



Cephalis spherical, with few small pores,, enclosed in the upper part of the thorax, which is 

 pear-shaped, spiny, and exhibits subregular, hexagonal pores, three times as broad as the bars. 

 From each hexagon corner a small thorn arises. 



Dimensions. Cephalis 0'04 diameter, thorax 0'25 long, 0'17 broad. 



Habitat. Central Pacific, Station 269, depth 2900 fathoms. 



Section III. TEICYETIDA, Haeckel, 1881, Prodromus, p. 426, 434. 



Definition. C yrtoidea trithalamia, with three-jointed shell, composed of cephalis, 

 thorax, and abdomen, with two separating transverse constrictions, an upper collar, and a 

 lower lumbar constriction. 



Synopsis of the Families and Subfamilies of Tricyrtida. 



Family LXV. ( Mouth open, . . . Theopilida. 



Podocyrtida. 

 Three radial apophyses. ( Mouth closed, . Theoperida. 



Family LXVI. ( Mouth open, . . Theophormida. 



Phormocyrtida. 

 Numerous radial apophyses. ( Mouth closed, . Theophaenida. 



Family LXVII. ( Mouth open, . . . Theocorida. 



Theocyrtida. 

 No radial apophyses. ( Mouth closed, . Theocapsida. 



(ZOOL. CHALL. EXP. PAKT XL. 1886.) Rr 165 



