REPORT ON THE RADIOLARIA. 1409 



roundish pores beyond the hnnbar stricture, and two to four succeeding transverse rows of irregular, 

 roundish, smaller pores. Mouth widely open, truncated. 



Dimfusiom. — Length of the three joints, a 0-02, h 0-05, c O'OG ; breadth, a OOo, h 0-08, c 0-07. 



Habitat. — Fossil in Barbados. 



Genus 616. TJieosyringium, Haeckel/ 1881, Prodromus, p. 434. 



Definition. — T li e o c o r i d a (vel Tricyrtida eradiata aperta) with cylindrical 

 abdomen, which is much narrower than the inflated thorax, and forms a slender, narrow 

 tube, with truncated mouth. Cephalis with a single horn. 



The genus Tlieosi/ ring i urn differs from the closely allied Theocyrtis, its ancestral 

 form, in the wide inflated thorax, which is much broader than the narrow tubular 

 abdomen. The mouth of the latter is small and truncate. 



1. Tlieosyringium tibia, n. sp. (PI. 68, fig. 4). 



SheU rough, very slender, with two distinct strictures. Length of the three joints = 1:3:4, 

 breadth = 1:2:1. Cephalis ovate, with a conical horn of the same length. Thorax ellipsoidal. 

 Abdomen cylindrical, as long as the two former joints together. Pores subregular, circular. 



mmensions. — Length of the tliree joints, a 0-0.3, h 0-09, c 012 ; breadth, a 0-03, 1 0-06, c 0-02. 



Hahitat. — Central Pacific, Station 263, depth 2650 fathoms. 



2. Tlieosyringium pij^etta n. sp. (PI. 68, fig. 5). 



SheU rough, inflated, with two sharp strictures. Length of the three joints = 2 : 7:9, breadth = 

 2:7:2. Cephalis conical, with a slender horn of half the length. Thorax subglobose. Abdomen 

 cylindrical, as long as the two former joints together. Pores subregular, circular. 



Dimensions. — Length of the three joints, a 0-02, h 0-07, c 0-09 ; breadth, a 0-02, I 0-07, c 0-02. 



Hahitat. — Central Pacific, Station 268, depth 2900 fathoms. 



3. Tlieosyringium siphonium, n. sp. 



Shell rough, inflated, with two deep strictures. Length of the three joints = 1:3:3, breadth = 

 1:2:1. Cephalis subspherical, with a stout pyramidal horn of twice the length. Thorax broad 

 ovate. Abdomen slender, inversely conical, as long as the thorax, and one-third as broad as 

 the base. Pores subregular, circular, hexagonaUy framed. (Similar to Eusyringium conosiphon, 

 PI. 78, fig. 10) but only with two strictures and three joints.) 



Diriunsions. — Length of the three joints, a 0-03, h 01, c 01 ; breadth, a 0-03, h 0-07, c 0'025. 



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



' rAeosi/nj!5fMtTO=Divine tube; 6iig, avoiyyiov. 



(ZOOL. CHALL. EXP. — PART XL. — 1886.) Rr 177 



