EEPOET ON THE RADTOLARIA. 647 



Dimensions. — Medullary shell 0'05 long, 0'035 broad ; cortical shell 012 long, 0-15 broad ; 

 gates 0-03 high, 0-06 broad. 



Habitat. — Southern Pacific, Station 290, surface. 



9. Tetrapyle cruciata, n. sp. 



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

 two on the poles of the transverse axis. Lateral girdle nearly circular, quite as long as broad. 

 Four gates kidney-shaped, twice as broad as high. On each half wing of the transverse girdle five 

 to six rows of subregular, circular pores. 



Dimensions. — Medullary shell 006 long, 0'05 broad; cortical sheU 0'16 long and broad; gates 

 0-05 high, 09 broad. 



Habitat. — South Atlantic, Station 330, surface. 



10. Tetrajyyle staurojjhora, n. sp. 



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

 two on the poles of the transverse axis. Lateral girdle elliptical, one and a half times as long as 

 broad. Four gates nearly hexagonal, quite as high as broad. On each half wing of the transverse 

 girdle three to four longitudinal rows of irregular, roundish pores. 



Dimaisions. — Medullary shell 0"06 long, 0'04 broad ; cortical shell 018 long, 012 broad ; 

 gates 8 high and broad. 



Habitat. — Western Tropical Atlantic, coast of Brazil, Eabbe, surface. 



11. Tetrcqyyle quadricornis, n. sp. 



Cortical shell thorny, with four strong horn-like curved spines, lying in the lateral plane and 

 converging in pairs towards the poles of the transverse axis. Lateral girdle elliptical, one and a 

 third times as long as broad. Four gates kidney-shaped, twice as broad as high. On each hal 

 wing of the transverse girdle four to five rows of irregular, roundish pores. (May be only the 

 young form of Pylonium quadricorne, PL 9, fig. 14.) 



Dimensions. — MeduUary shell O'OS long, 0-04 broad; cortical shell 010 long, 012 broad; 

 gates 0-03 high, 0-07 broad. 



Habitat.— -V&cific, central area, Stations 270 to 274, surface. 



12. Tetrapyle tetracantha, n. .sp. 



Cortical shell thorny, with four strong radial spines lying in the lateral plane and in pairs in 

 its two crossed diagonal axes. Lateral girdle elliptical, constricted in the middle, nearly twice as 

 long as broad. Four gates kidney-shaped, one and a half times as broad as high. On each half 

 wing of the transverse girdle three to four longitudinal rows of large, irregular, roundish pores. 



