REPORT ON THE RADIOLARIA. 1137 



5. Tripocalpis cortinaris, n. sp. (PL 97, fig. 3). 



Shell hemispherical, one and a half times as broad as long, with regular, circular, hexagonally 

 framed pores. Apical horn stout, three-sided pyramidal, with three serrate edges. From the base 

 of the latter arise three strongly dentate and curved lateral ribs, with recurved teeth, and these 

 are prolonged into the serrate convex edge of the three basal feet, which are crescentic and twice 

 as long as the shell. 



Dimensions. Shell 0'07 long, O'l broad; horn 0'06 long, feet 014 long. 



Habitat.- Indian Ocean, Cocos Islands (Eabbe), surface. 



Genus 497. Tripodonium, 1 Haeckel, 1881, Prodromus, p. 428. 



Definition. A rchipilida (vel Monocyrtida triradiata aperta) with three 

 lateral ribs prolonged into three terminal feet. Apex without horn. 



The genus Tripodonium differs from the preceding Tripocalpis, its probable 

 ancestral form, only in the loss of the apical horn (already very small in some forms of 

 the latter). It bears therefore to the latter the same relation that Sethopilium does 

 to Dictyophimus. 



1. Tripodonium campanulatum, n. sp. 



Shell campanulate, somewhat broader than high, with regular circular pores, twice as broad 

 as the bars. Three broad lateral wings, lamellar, triangular, are prolonged over the peristome into 

 three short triangular lamellar feet, one-fourth as long as the shell. 



Dimensions. Shell O08 long, 0'09 broad; feet 0'02 long. 



Habitat. Central Pacific, Station 272, depth 2600 fathoms. 



2. Tripodonium ovatum, n. sp. 



Shell ovate, one and one-third times as long as broad, with numerous and small circular pores, 

 scarcely as broad as the bars. Three prominent longitudinal ribs, arising in the lower half of the 

 shell-wall, are prolonged into three divergent conical curved feet, about half as long as the shell. 



Dimensions. Shell 0'12 long, 0'09 broad ; feet 0'06 long. 



Habitat. Central Pacific, Station 266, depth 2750 fathoms. 



Genus 498. Tripterocalpis, 2 Haeckel, 1881, Prodromus, p. 428. 



Definition. Archipilida (vel Monocyrtida triradiata aperta) with three 

 lateral wings and a peristomial corona of numerous terminal feet. Shell ovate, with 

 constricted mouth, without apical horn. 



1 Tripodonium =-- Shell with three feet. 2 Tnpterocalpis = 1Jm with three wings; t^-n^;, ****!;. 



(ZOOL. CIIALL. EXP. PART XL. 1886.) El 143 



