1490 THE VOYAGE OF H.M.S. CHALLENGER. 



6. Eucyrtidium spinosum, n. sp. 



Shell spiny, slender, ovate, without external strictures, but with seven or eight internal septal 

 rings. Conical spines of different lengths are scattered over the whole surface. All joints have 

 nearly the same length ; the sixth is the broadest. Cephalis conical, with one large and two or 

 three smaller conical horns. Mouth constricted, half as broad as the shell. Pores irregular, 

 roundish, double-edged, three to four on the length of each joint. 



Dimensions. Length of the shell (with eight joints) 016, length of each joint 0'02; greatest 

 breadth (on the sixth joint) 0'06. 



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



7. Eucyrtidium chrysalidium, n. sp. 



Shell spiny, spindle-shaped, with four to five slight strictures, above each stricture a circle or 

 girdle of conical spines (as in the similar Cyrtophormis cingulata, PL 78, fig. 18). All joints (except 

 the first) have the same length. Cephalis subspherical, with a bunch of divergent spines. Mouth 

 constricted, only one-third as broad as the third joint, which is the broadest. Pores subregular, 

 circular, four to five on the length of each joint. 



Dimensions. Length of the shell (with six joints) 018, length of each joint 0'032; greatest 

 breadth 0-08. 



Habitat. South Pacific, Station 302, depth 1450 fathoms. 



Subgenus 3. Artocyrtis, Haeckel. 



Definition. Joints of the shell of very different lengths. Surface smooth or rough, 

 without spines. 



8. Eucyrtidium profundissimum, Ehrenberg. 



Eucyrtidium profundissimum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 293, 

 Taf. vii. fig. 12. 



Shell smooth, campanulate, ovate, with three internal septal rings. Four joints of different 

 lengths. Cephalis subspherical, with a small bristle-shaped horn. Thorax campanulate, nearly twice 

 as long as each of the two following joints, which are nearly equal in breadth. Terminal mouth 

 wide open, little constricted. Pores very small and numerous, regular, hexagonal. 



Dimensions. Length of the shell (with four joints) 012 ; length of the thorax 0'05, breadth 

 0-07. 



Habitat Pacific ; many Stations (Stations 206, 225, 253, 265, &c.), in depths between 2000 

 and 4000 fathoms. 



