1500 THE VOYAGE OF H.M.S. CHALLENGER. 



1. Siphocampe tubulosa, n. sp. (PI. 79, fig. 13). 



Shell slender, nearly spindle-shaped, with eight deep transverse strictures, and elegant 

 longitudinal ribs. Nine joints slightly different in length and shape. CephaHs flat, cap-shaped, 

 with three or four transverse rows of small pores, and a cylindrical, oblique tubule of twice the 

 length. Each successive joint with a single transverse row of regular, circular pores at its lower 

 edge, separated by divergent, longitudinal ribs. Last joint shorter, with a hyaline annular 

 peristome of the same length. Mouth half as broad as the middle part of the shell. 



Dimensions. — Length of the shell (with nine joints) 0-24; length of each joint (on an 

 average) 0-02 to O'OS ; breadth 0-08. 



Habiiai. — Western Tropical Pacific, Station 225, depth 44*75 fathoms. 



2. Siphocampe annulosa, n. sp. (PI. 79, fig. 10). 



SheU slender, subcylindrical, with nine slight transverse strictures, and interrupted longitudinal 

 ribs. Ten joints nearly equal in length and shape, excepting the two first, which together form a 

 hemispherical cephalothorax, with six to eight transverse rows of pores. Tubule of the cephalis 

 short and wide, truncate, conical. Each of the eight abdominal joints with a single transverse 

 row of small pores. Mouth constricted, without tubulosa peristome, half as broad as the shell. 



Bimevsions. — Length of the shell (with ten joints) 0'18 ; length of each joint (on an average) 

 0-02, breadth 0-07. 



Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 



3. Siphocampe caminosa, n. sp. (PI. 79, fig. 12). 



SheU slender, subcylindrical, with six deep trauverse strictures. Seven joints nearly equal in 

 length and breadth. Cephalis hemispherical, with an oblique, cylindrical tubule of twice the length 

 (in the figure the greater part is broken away). Small circular pores in transverse rows and in 

 variable number ; usually three rows in the first and the last joint, five rows in the fourth joint, four 

 rows in each of the other joints. Mouth constricted, with a short tubulose peristome, only one- 

 third as broad as the shell. 



Dimensions. — Length of the shell (with seven joints) O^IB ; length of each joint (on an 

 average) 0-025, breadth 0-055. 



Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 



4. Siphocampe erucosa, n. sp. (PL 79, fig. 11). 



Shell slender, nearly spindle-shaped, with five slight transverse strictures. Six joints nearly 

 equal in length. The two first joints are united, and form together a hemispherical cephalothorax, 

 with a short, oblique, cylindrical tubule. Pores regular, circular, double-contoured, in regular, 

 transverse rows ; two rows in the first and the last joints, four rows in each of the four middle 

 joints. Mouth constricted, without peristome, only one-third as broad as the shell. 



