REPORT ON THE RADIOLARIA. 1519 



Genus 655. Artocapsa} Haeckel, 1881, Prodromus, p. 438. 



Definition. — S tichocapsida (vel Stichocyxtida eradiata elausa) with an apical 

 horn on the cephahs, and a basal terminal spine on the last joint. 



The genus Artocapsa difiers from Cyrtocapsa, its ancestral form, by the development 

 of a vertical terminal spine, or a bunch of spines, on the base of the last joint, and 

 bears therefore to it the same relation as Rhopalatractus does to Rhopalocanium. 



1. Artocapsa fiisiformis, n. sp. (PI. 76, fig. 5). 



Shell spindle-shaped, rough, with five slight strictures, decreasing uniformly from tlie broader 

 middle towards both poles, with a strong, pyramidal, terminal spine at each pole. Length of the 

 six joints = 2:5:3:3:2:5. Cephalis hemispherical, hyaline, without pores, its horn half as large 

 as tlie basal spine. Pores small and numerous, subregular, circular. 



Diincnsions. — Lengtli of the shell (with six joints) 0'2, breadtli 0'09. Length of the single 

 joints, a 0-02, 6 0-05, c 003, d 003, c 0-02. / 0-05. 



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



2. Artocapsa spinosa, n. sp. (PL 76, fig. 10). 



Shell spindle-shaped, spiny, with five distinct strictures. Length of the six joints = 

 2:3:2:5:4:4. The fourth joint is the broadest, and much larger than the five other joints. 

 The first and the last joints are similar in size and form, hemispherical, armed with some larger, 

 irregular, conical spines. Pores irregular, roundish, of variable sizes. 



Dimensions. — Length of the shell (with six joints) 0'2, breadth 0'09. Length of the single 

 joints, a 0-02, h 0-03, c 0-02, d 0-05, c 004,/ 0-04. 



Hahitat. — Central Pacific, Station 266, depth 2750 fathoms. 



3. Artocapsa infraculeata, Haeckel. 



Eucyrtidium infraculeatum, Stcihr, 1880, Paleeontogr., vol. xxvi. p. 106, Taf. iv. fig. 13. 



Shell subcylindrical, rough, with five annular septa. Length of the six joints = 2:3:4:4:4:3. 

 The third, fourth, and fifth joints are nearly equal in length and breadth, whilst the second and 

 sixth are cupola-shaped. The cephalis is very small, subspherical (regarded by Stohr as a " large 

 pore "), and bears a short conical horn. The last joint bears a buncli of basal spines. 



DimevMons. — Length of the shell (with six joints) 0-2, breadth 0-09. Length of the cephalis 

 0'02, second and sixth joints 0'03, third, fourth, and fifth joints 0-04. 



Habitat. — Fossil in Tertiary rocks of Sicily ; Grotte (Stohr), Caltanisetta \,Haeckel). 



1 v^r(ocapsa = Bread-shaped capsiile ; ajroc, xdi^a. 



