REPORT ON THE RADIOLARIA. 1439 



three large, triangular, widely divergent wings or ribbed solid spines, nearly as long as the shell. 

 The breadth of the joints increases gradually ; the last joint is the broadest, with wide open mouth. 

 Pores subregular, circular. 



DimcTisioiis. — Length of the shell (with six joints) 0-23, breadth 01. Length of the single 

 joints, a 002, h 0-05, c 004, d 0-03, e 0-03, / 0-06. 



Hahitat. — Fossil in Barbados. 



8. Stichopilium pectinatum, n. sp. 



Shell slenderly conical, with nine sharp strictures. AU ten joints have nearly equal length, and 

 increase gradually in breadth ; the last joint is the broadest, and twice as long as each of the others, 

 with wide open laouth, Cephalis subspherical, with a conical horn of the same length. Each joint 

 (excepting the first and the last) bears three lateral, nearly horizontal spines, and the bases of all the 

 spines are connected by three longitudinal, divergent ribs. Pores subregular, hexagonal. (Similar 

 to SticJwpc7-a pectinafa, PI. 75, fig. 11.) 



Dimensions. — Length of the shell (with ten joints) 0'32, l^readth O'l. 



Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 



9. StichopUium thoracopterum, n. sp. 



SheU slenderly ovate, twice as long as broad, with eleven slight annular strictures. The twelve 

 joints (excepting the second) are of nearly equal length, or alternately longer and shorter. The eighth 

 joint is the broadest, one and a half times as broad as the slightly constricted mouth. Cephalis 

 small, hemispherical, with a pyramidal horn of twice the length. Thorax (or second joint) cam- 

 panulate, twice to three times as long as each of the eleven other joints, with three longitudinal ribs, 

 prolonged into three divergent, slender, free spines. Pores small, regular, hexagonal. 



Dimensions. — Length of the shell (with twelve joints) 0"22, breadth Oil. Length of each 

 joint (on an average) 0"015 to 0'0l7, thorax 0'035. 



Habitat. — South Pacific, Station 296, depth 1825 fathoms. 



Genus 627. Artopilium,^ Haeckel, 1881, Prodromus, p. 437. 



Definition. — S tichopilida (vel Stichocyrticla triradiata aperta) with three 

 latticed lateral ribs or mngs, without terminal feet. Cephalis with a horn. 



The genus Artopilium (including also the genera Trictenartus, Pterocorythium, 

 Stichopterygium, and Clathropyrgus of my Prodromus) has a shell of the same form as 

 the preceding Stichop>ilium, but it differs in the fenestration of the three lateral rfbs 

 or wings, which in the latter are solid. The limit between the two genera is often not 



' Artopilium =:ho9.i-h.aX; d^oi, ■ni'h.tou. 



