1494 THE VOYAGE OF H.M.S. CHALLENGER. 



and the last joints are the longest, the third is the broadest. Mouth slightly constricted (broken 

 off in Stb'hr's figure). Cephalis small, subspherical, with a small, oblique, curved horn. Pores 

 irregular. 



Dimensions. Length of the shell (with seven joints) 0'2 ; length of the single joints, between 

 0-02 and 0'04, breadth 0'06 to 0'08. 



Habitat. Fossil in Sicily (Grotte, Caltanisetta). 



20. Eucyrtidium stohrii, n. sp. 



Shell smooth, spindle-shaped, gradually diminishing towards both ends, with eight to ten distinct 

 strictures. Nine to eleven joints of different lengths ; the two or three middle joints fifth, sixth, 

 and seventh longer and broader than the other joints ; the broadest is the fifth joint, which is twice 

 to three times as long as the first and last joints. Cephalis subspherical, with a conical horn of 

 the same length. Terminal mouth strongly constricted, one-half or one-third as broad as the fifth 

 joint. Pores small, regular, circular. 



Dimensions. Length of the shell (with ten joints) 0'22 ; length of the largest (fifth joint) 0'03, 

 breadth 0'09. 



Habitat. Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms. 



21. Eucyrtidium scalarium, n. sp. 



Shell smooth, slender, ovate, with nine to ten deep strictures, and ten to eleven separate 

 step-like joints of different lengths. The sixth joint is the longest, twice as long as the fourth, and 

 three times as long as the third and the last joint ; the seventh and eighth joints are the broadest, 

 one and a half times as broad as the wide mouth. Cephalis hemispherical, with a short pyramidal 

 horn of the same length. Pores small and numerous, subregular, square, in regular transverse rows ; 

 six rows in the sixth joint, three rows in the last joint. (Somewhat similar to Spirocyrtis scalaris, 

 PI. 76, fig. 14, but ovate, not conical and not spiral.) 



Dimensions. Length of the shell (with eleven joints) 0'22, breadth Oil ; length of the last 

 joint O'Ol, of the sixth 0'03. 



Habitat. North Atlantic, Station 64, surface. 



Subgenus 4. Acanthocyrtis, Haeckel, 1881, Prodromus, p. 437. 

 Definition. Joints of the shell of very different lengths. Surface spiny. 



22. Eucyrtidium tricinctum, n. sp. (PL 78, fig. 13). 



Shell spiny, spindle-shaped, with three distinct strictures. Four joints of different lengths, the 

 first and third half as long as the second and fourth ; the third joint is the broadest, four times as 



