1504 THE VOYAGE OF H.M.S. CHALLENGER. 



hexagonal pores. The fourth and fifth joints are the broadest. The constricted mouth is twice as 

 broad as the hemispherical cej)halis, half as broad as the fourth joint. 



Dimensions. — Length of the shell (with ten joints) 0'2, of each joint 0'02 ; breadth of the fourth 

 joint 0-06, mouth O'OS. 



Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 



Subgenus 2. LitJiocampium, Haeckel, 1881, Proclromus, p. 437. 

 Definition. — The joints of the shell are very clifFereut in length. 



7. Lithocampe ovata, n. sp. (PL 77, fig. 1). 



Shell smooth, urceolate or ovate, with three sharp strictures. Pour joints of different lengths, 

 having the proportion 1 : 2 : 2 : G. The fourth joint is inflated and the broadest. The mouth is con- 

 stricted, short, tubular, of the same breadth as the hemispherical cephalis. Pores small, circular, 

 in regular transverse rows ; four rows in the first, four in tlie second, two in the third, and five in 

 the fourth joint. The middle stricture is crossed by longitudinal ribs. 



Dimensions. — Length of the shell (with four joints) Oil. Length of the single joints, a O'Ol, 

 b 0-02, c 0-02, d 0-06 ; greatest breadth 0-055. 



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



8. Lithocampe aquilonaris, Haeckel. 



Litliocam^pe aquilonaris, Haeckel, 1862, Monogr. d. Radiol., p. 317. 



Eucyrtidium aquilonare, Bailey, 1856, Amer. Journ. Sci. and Arts, vol. xxii. p. 4, pi. i. fig. 9. 



Shell smooth, subconical, with three distinct strictures. Four joints of different lengths, having 

 the proportion 3:1:3:4. The fourth joint is the broadest, suddenly constricted, with a short tubular 

 mouth of half the breadth. Pores subregular, circular, in transverse rows ; three rows in the first 

 joint, two in the second, four in the third, and three in the fourth joint. 



Dimensions. — Length of the shell (with four joints) Oil. Length of the single joints, a 0-03, 

 b 0-01, c 0-03, d 0-04; breadth Q-OG. 



Habitat. — North Pacific, Kamtschatka (Bailey), Station 241, depth 2300 fathoms. 



9. Lithocampe quadrarticulata, Haeckel. 



Lithocampe quadraHiculata, Haeckel, 1862, Monogr. d. Radiol., p. 319. 



Eucyrtidium quadrarticulatum, Ehrenberg, 1861, Monatsber. J. k. preuss. Akad. d. "Wiss. Berlin, 

 p. 299. 



Shell smooth, spindle-shaped, with three deep strictures. Four joints of different lengths = 

 1:3:4:3. The third joint is the broadest, being twice as broad as the constricted mouth of the 

 fourth joint. Pores small, regular, circular, in transverse rows ; two being in the first, three in the 

 second, four in the third, three in the fourth joint. 



