1028 THE VOYAGE OF H.M.S. CHALLENGER. 



9. Tripospyris capitata, n. sp. (PL 84, fig. 1). 



Shell subspherical, spiny, with slight sagittal stricture and ovate internal ring. Basal plate 

 with four large collar pores. Facial plate with three pairs and occipital plate with two pairs of 

 large roundish annular pores ; lateral lattice with smaller irregular pores. Apical horn and the 

 three feet subcylindrical, about half as long as the shell, straight, divergent, with a spherical, spinulate 

 knob at the distal end. 



Dimensions. Shell 0'09 long, 01 broad ; horn and feet 0'05 to 0'06 long. 



Habitat. Central Pacific, Station 266, depth 2750 fathoms. 



10. Tripospyris clavata, Haeckel. 



Ceratospyris clavata, Butschli,1882, Zeitschr. f . wiss. Zool.,vol. xxxvi. p. 539,Taf. xxxii. fig. 13,a-c. 



Shell subspherical, compressed, rough, with slight sagittal stricture and ovate internal primary 

 ring. Basal plate with four large collar pores (fig. 13,a, loc. cit.). The other lattice-work with 

 irregular small roundish pores. Apical horn and the three feet short and thick, scarcely half as 

 long as the shell, with a roundish spinulate knob at the distal end. 



Dimensions. Length of the shell 0'07 long, 0'08 broad ; horn and feet 0'02 to 0'03 long. 



Habitat. Fossil in Barbados. 



11. Tripospyris tessaromma, n. sp. 



Shell nearly cubical, spiny, with deep sagittal stricture and subcircular ring. Basal plate with 

 four large collar pores. Facial and occipital plates each also with two pairs of large square 

 annular pores ; lateral pores irregular polygonal. Apical horn half as long as the feet, which 

 are three times the length of the shell, cylindrical, slightly curved. 



Dimensions. Shell 01 long, 012 broad ; horn 015 long, feet 0'3 long. 



Habitat. Tropical Atlantic, Station 348, depth 2450 fathoms. 



Subgenus 4. Tripospyromma, Haeckel. 



Definition. Basal plate with six or more collar pores. Commonly two small 

 anterior jugular pores, two large middle cardinal pores, and two small posterior cervical 

 pores ; sometimes several small accessory collar pores. 



12. Tripospyris hexomma, n. sp. (PI. 95, fig. 4). 



Shell thorax-shaped, tuberculate, with deep sagittal stricture and semicircular internal primary 

 ring. Basal plate with three pairs of pores. Facial plate with two pairs, occipital plate with 

 four pairs of large annular pores. Lateral pores smaller, irregular, polygonal. Apical horn and 

 caudal foot half as long as the shell and as the two pectoral feet ; all four spines cylindrical, two 

 to three times as long as the shell, slightly curved. 



Dimensions. Shell 01 long, 012 broad ; horn and feet 0'2 to 0'4 long. 



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



