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



7. Octopyle tetrastyle, n. sp. 



Cortical shell lentelliptical, with rough surface and four angular radial spines in the lateral 

 plane, opposite in pairs in two crossed diagonals. Lateral girdle nearly rectangular (each angle 

 with one spine), one and a third times as long as broad. Sagittal septum longer than the hexagonal 

 medullary shell. Eight gates egg-shaped. 



Dimensions. Length of the medullary shell 0'05, breadth 0'03 ; length of the cortical shell 

 016, breadth 012. 



Habitat. North Atlantic, Station 354, surface. 



8. Octopyle tetraptera, n. sp. 



Cortical shell quadrangular, with thorny surface and four latticed wing-like prolongations on 

 the corners of the quadrangle, opposite in pairs in two crossed diagonals, each wing supported by a 

 strong radial spine. Lateral girdle quadrangular, one and a half times as long as broad. On the 

 isthmus of the transverse girdle four pores. Sagittal septum longer than the hexagonal medullary 

 shell. Eight gates triangular. 



Dimensions. Length of the medullary shell 0'07, breadth 0'04; length of the cortical shell 

 0-24, breadth 016. 



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



9. Octopyle stenozona, n. sp. (PL 9, fig. 11). 



Cortical shell quadrangular, with thorny surface, and four conical spines in the lateral plane, 

 on the points, where both cortical girdles are crossed. Lateral girdle very narrow, nearly square, 

 with rounded corners, of equal length and breadth. On the isthmus of the narrow transverse 

 girdle only one pore. Sagittal septum of the same length as the subspherical medullary shell. 

 Eight gates irregular roundish or nearly circular. 



Dimensions. Diameter of the medullary shell 0'04, of the cortical shell 014. 



Habitat. Tropical Atlantic, Station 338, depth 1990 fathoms. 



10. Octopyle euryzona, n. sp. 



Cortical shell nearly quadrangular, very thorny, with four bunches of stronger radial spines on 

 the four corners. Lateral girdle broad, with rounded edges of the quadrangle, little longer than 

 broad. On the isthmus of the broad transverse girdle four pores. Sagittal septum of the same 

 length as the elliptical medullary shell, with many radial beams. Eight gates nearly square. 



Dimensions. Length of the medullary shell 0'05, breadth 0'035 ; length of the cortical shell 

 016, breadth 014. 



Habitat. Southern Atlantic, Station 332, depth 2200 fathoms. 



