REPORT ON THE RADIOLARIA. 707 



3. Streblacantha hastigerina, n. sp. 



Shell nearly spherical, clustered, with nine to eleven nearly spherical chambers of rapidly 

 increasing size, the tenth chamber about six times as broad as the first. Breadth of the shell 

 nearly'equal to the height. Pores subregular, circular, of about the same breadth as the bars. 

 Surface bristly, covered with numerous very thin and long, needle-shaped radial spines, longer than 

 the diameter of the shell. (Resembles closely Hastiyerina.) 



Dimensions. Breadth of the shell 0'18, height O15. 



Habitat. Pacific, central area, Station 271, depth 2425 fathoms. 



Genus 312. Streblopyle, 1 n. gen. 



Definition. S treblonida with trizonal lentelliptical medullary shell (composed 

 like Larnacilla of three elliptical dimensive girdles surrounding one simple central 

 primordial chamber). From this begins a screw-like series of spirally ascending chambers. 

 Surface smooth or thorny, without radial spines. 



The genus Streblopyle presents externally the same appearance and contour as Streb- 

 lonia, and is composed like this of a variable number of chambers, ascending screw-like 

 around the axis of the spiral shell. The first or primordial chamber, however, in which 

 the growth begins, is in Streblonia a simple spherical shell, but in Streblopyle a 

 trizonal shell or Larnacilla-shell (compare above, p. 600). The chambers are very 

 incompletely separated, and comparatively much larger, their number much smaller than 

 in Streblonia. The structure in the species of this genus is difficult to understand. 



1. Streblopyle helicina, n. sp. (PL 49, fig. 9). 



Shell helicoid, one and a third times as high as broad, with eight to twelve incomplete 

 semizonal chambers, ascending spirally from the lateral half girdle of the lentelliptical medullary 

 shell, octopyle-shaped, and enveloping it in three to four spiral turnings. The height of the whole 

 cortical shell equals nearly five times the height of the trizonal medullary shell. Pores irregular, 

 roundish. Surface of the shell rough or nearly smooth. (This species seems to be nearly allied to 

 Spironium octonium.) 



Dimensions. Breadth of the spiral cortical shell 018, height O24 ; breadth of the medullary 

 shell 0-04, height 0'05. 



Habitat. Pacific, central area, Station 266, depth 2750 fathoms. 



2. Streblopyle spirulina, n. sp. 



Shell egg-shaped or nearly spherical, about as high as broad, with eight to nine semizonal 

 chambers, ascending spirally from the subspherical trizonal medullary shell, and enveloping it in 



1 Streblopyle = Screw-shell with gates ; ar^i^n, xv\rt. 



