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



5. Tetrapyle cardiopyle, n. sp. 



Cortical shell rough, without radial spines. Lateral girdle with hexagonal contour, nearly 

 cylindrical in the middle part, conical at both ends, twice as long as broad. Four gates heart- 

 shaped, about as high as broad. On each half wing of the transverse girdle three to four 

 longitudinal rows of subregular, polygonal pores. 



Dimensions. Medullary shell 0'04 long, 0'02 broad ; cortical shell 014 long, 0'07 broad ; gates 

 0'05 high and broad. 



Habitat. Eastern Tropical Atlantic, Station 348, depth (2450) fathoms. 



Subgenus 2. Tetrapylura, Haeckel. 

 Definition. Cortical shell armed with large, symmetrically disposed spines. 



6. Tetrapyle fusif or mis, n. sp. 



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

 Lateral girdle spindle-shaped, one and a half times as long as broad. Four gates kidney-shaped, 

 twice as broad as high. On each half wing of the transverse girdle four to five longitudinal rows 

 of irregular, roundish pores. 



Dimensions. Medullary shell 0'07 long, 0'05 broad; cortical shell 018 long, 0'12 broad; gates 

 0-04 high, 0-08 broad. 



Habitat. Western Tropical Atlantic, Mexican Gulf Stream, depth 1500 fathoms, Schaffner. 



7. Tetrapyle pleuracantha, n. sp. (PL 9, fig. 9). 



Cortical shell rough, with two strong conical spines on the poles of the transverse axis. 

 Lateral girdle elliptical, one and a half times as long as broad. Four gates subcircular or nearly 

 hexagonal, about as high as broad. On each half wing of the transverse girdle three to four 

 longitudinal rows of very irregular pores. 



Dimensions. Medullary shell 0'045 long, 0'035 broad; cortical shell 01 G long, Oil broad; 

 gates 0'045 high and broad. 



Habitat. Western Tropical Pacific, off New Guinea, Stations 222 to 224, depths 1850 to 2450 

 fathoms. 



8. Tetrapyle transversa, n. sp. 



Cortical shell thorny, with two strong conical lateral spines on the poles of the transverse 

 axis. Lateral girdle elliptical, only four-fifths as long as broad. Four gates elliptical, twice as broad 

 as high, with two prominent spines on the poles of the longitudinal axis of the medullary shell. 

 On each half wing of the transverse girdle five to six longitudinal rows of subregular, roundish 

 pores. (Similar to Octopyle transversa, but without sagittal septum and with stronger lateral 

 spines.) 



