REPORT ON THE RADIOLARTA. 243 



3. Elatomma jiiniperinum, n. sp. (PL 28, fig. 8). 



Cortical shell tliiii walled, with regular, polygonal, or roundish pores, twice to four times as 

 broad as the bars, connected with the small medullary shell by about twenty thin radial beams. 

 Inner shell only one-eighth as broad as the outer, with few irregular, polygonal meshes. Surface 

 covered with very numerous (one hundred to one hundred and fifty or more) branched conical radial 

 .spines, one-third as long as the shell radius, with six to twelve short lateral Ijrauches. 



Dimensions. — Diameter of tlie outer shell 0-2, inner 0-025; cortical pores 0'08 to 0'016, bars 

 0-004 ; length of the s]iines 0-04. 



Habitat. — Central Pacific, Station 271, surface. 



4. Elatomma jxniciU us, u. sp. 



Cortical sliell thin walled, with irregulai", polygonal pores, twice to four times as broad as the bars, 

 connected with the medullary shell by twenty (or more ?) very tliin beams. These are prolonged 

 outside into twenty straight, three-sided prismatic, radial spines as long as the radius, with a brush- 

 like bunch of six to nine short, irregularly ramified branches at the end. Medullary shell very 

 delicate (half as broad as the outer), with regular, hexagonal meshes and thread-like bars. 



Dimcnsio'iis. — Diameter of the outer shell 0-15, inner 0-08 ; length of the spines O'OS. 



Habitat. — West coast of Norway, Bergen, Haeckel. 



5. Elatomma u-regulare, n. sp. 



Cortical sliell thin walled, with irregular, polygonal, or roundish meshes, twice to six times as 

 broad as the bars ; the medullary shell of the same structure, half as broad, with smaller irregular 

 pores. Forty to sixty curved, three-sided, radial spines, as long as the shell, with a bunch of very 

 irregular, curved, and partly ramified branches at the distal end. 



Dimensions. — Diameter of the outer shell 0-2, inner O'l ; length of the spines 0-2, breadth 0-01. 



Habitat. — North Atlantic, Gulf Stream, Faeroe Channel, surface, John Murray. 



■ Genus 97. Le2:)tosphcera,^ n. gen. 



Definition. — A s t r o s p h aj ri da with two extracapsular cortical sliells without 

 by-spines, connected by long prismatic radial spines. 



The genus Leptosphcera, together with the three following genera, forms the very 

 peculiar and typical small group of S p h je r o i d e a 'W'hich we call the Diplosph^rida 

 (wdth four genera and twenty-four species) ; their shell is comjiosed of two concentric 

 spheres as in the three foregoing genera; but whilst in these the inner shell is an intra- 

 capsular medullary shell and the outer an extracapsular cortical shell, in the Diplosphserida 



^ Zre;)Jo.5p7ifEra = Delicate sphere; TistttoV, !?«??«. 



