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



5. Amphipyle tetraceros, n. sp. (PI. 9, fig. 5). 



Cortical shell with smooth surface, and with four strong conical spines in the lateral plane, 

 opposite in pairs on the ends of the concave lateral crests (one pair on the end-points of the 

 lateral line of each wing) ; four to five longitudinal rows of irregular, roundish pores on each half 

 wing of the cortical girdle. Surface of the medullary shell spiny. 



Dimensions. Length of the medullary shell 0'08, breadth of the same 0'05 ; length of each 

 lateral wing 016, breadth 0'04. 



Habitat. Pacific, central area, Station 271, surface. 



6. Amphipyle stauroceros, n. sp. 



Cortical shell with four strong conical spines, two on the poles of the longitudinal axis, two 

 opposite on the poles of the transverse axis (perpendicular to the former). Three to four longi- 

 tudinal rows of irregular, roundish pores on each half wing of the cortical girdle, about six pores in 

 the longest row. Lateral crest convex. 



Dimensions. Length of the medullary shell 0'05, breadth 0'03 ; length of each lateral wing 

 015, breadth 0'08. 



Habitat. Pacific, central area, Station 268, depth 2900 fathoms. 



7. Amphipyle amphiptera, n. sp. (PI. 9, fig. 7). 



Cortical shell with six strong conical spines, lying in the lateral plane in three parallel longi- 

 tudinal lines ; two on the poles of the longitudinal axis, two others on the poles of the wing axes, 

 which are parallel to the former. Two to three longitudinal rows of irregular, roundish pores on 

 each half wing of the cortical girdle, about eight pores in the longest row. Lateral crest convex, 

 thorny. 



Dimensions. Length of the medullary shell 0'06, breadth - 045 ; length of each lateral wing 

 0-09, breadth 0'035. 



Habitat. Western Tropical Pacific, Station 224, surface. 



8. Amphipyle hexaceros, n. sp. 



Cortical shell thorny, with six strong conical spines, lying in the lateral plane ; two on the 

 poles of the lateral axis (in the central point of each wing), two on the end-points of the 

 triangular crest of each wing (on both poles of the longitudinal wing-axis). 



Dimensions. Length of the medullary shell 0'06, breadth 0'04 ; length of each lateral wing 

 013, breadth 0'07. 



Habitat. South Pacific, Station 291, surface. 



