REPORT ON THE RADIOLARIA. 1453 



three divergent, irregularly dentate ribs, which at the second joint bear stronger, pyramidal teeth, 

 also at the third stricture a strong, terminal tooth. Fourth joint without ribs, inversely conical, 

 with a strong, conical, terminal spine of half the length on the basal pole. Pores subregular, circular, 

 double-edged. 



Dimensions. Length of the shell (with four joints) 015. Breadth of the third (broadest) joint 

 0-08. Length of the single joint,, a 0'02, b O03, c 0'05, d 0'05. 



Habitat. Western Tropical Pacific, Station 225, depth 4475 fathoms. 



Family LXIX. PHORMOCAMPIDA, n. fam. 



Artophormida et Ariopliienida, Stichophormida et Stichophaenida, Haeckel, 1881, Prodromus, pp. 438, 439. 



Definition. S tichocyrtida multiradiata. (Cyrtoidea with an annulated 

 shell, divided by three or more transverse constrictions into four or more annular 

 joints, with numerous, four to nine or more, radial apophyses.) 



The family Phormocampida comprises those Cyrtoidea in which the 

 lattice-shell is composed of numerous (four to eight or more) annular joints, and bears 

 numerous (four to eight or more) radial apophyses. We divide it into two 

 subfamilies, differing in the shape of the terminal mouth. This is a simple 

 wide opening in the Stichophormida (and the united Artophormida), closed by a lattice- 

 plate in the Stichophsenida (and the united Artophsenida). The phylogenetic origin of 

 the Phormocampida may be found in the Phormocyrtida. 



Three fossil forms only of Phormocampida were hitherto known, two of which were 

 described by Stohr as Eucyrtidium acutatum and Lithocampe jimbriata, the third by 

 Ehrenberg as Eucyrtidium barbadense ; the latter belongs to Artophormis, the two 

 former to Oyrtophormis. All the other Phormocampida here described, forming 

 together thirty -one species, are new; twenty -two of them belong to the Stichophor- 

 mida, and nine to the Stichophsenida. The latter are disposed in two, the former in 

 four genera. 



The number of the radial apophyses is sometimes six or nine, sometimes twelve or 

 more, usually a multiple of three. They are either lateral ribs or wings (PI. 75, 

 figs. 2, 5, 12), or terminal feet (PI. 77, figs. 13 to 18). Usually they are solid, 

 not latticed, and not strongly developed. The majority of Phormocampida have pro- 

 bably been derived from Phormocyrtida by growth of the abdomen, which becomes 

 annulated by transverse constrictions. Some forms, however, may be derived 

 from similar Podocampida, by interpolation of three to six or more secondary apophyses 

 between the three primary or perradial apophyses. 



