REPORT ON THE RADIOLARIA. 1405 



5. Lophoconus cervics, Haeckel. 



? Eucyrtidium cervus, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, 

 Taf. ix. fig. 21. 



Shell conical, smooth, without external stricture, but with two internal annular septa. Length 

 of the three joints = 1:2:4, breadth = 1:3:6. Cephalis campanulate, with two to six divergent, 

 partly ramified horns. Pores in tlie thorax regular, circular, in tlie abdomen three to four times 

 as larse, regular, hexagonal. 



Dimensions. — Length of the three joints, a, 0-02, h 0-04, c 0-08 ; breadth, a 0-02, h 0-06, c 0-12. 



Habitat. — Indian Ocean, Cocos Islands (Eabbe), surface (? Zanzibar, 2200 fathoms, PuUen). 



6. Lophoconus rhinoceros, n. sp. (PL 69, fig. 2). 



Shell campanulate, conical, rough, with two sharp strictures. Length of the three joints = 

 1:2:3, breadth = 1:3:4. Cephalis subspherical, with numerous very small pores, and two stout, 

 divergent, pyramidal horns, the major of which is longer, the minor shorter, than the cephalis. 

 Thorax campanulate, with small, regular, cii-cular pores. Abdomen inflated, with thickened margin 

 at the wide open mouth, and with irregular, roundish pores, twice to four times as broad as those 

 of the thorax. 



Dimensions. — Length of the three joints, a 0'03, h 0'05, c 0'09 ; breadth, a 0'04, l 0'09, c 012. 



Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 



Genus 615. Theocyrtis,^ n. gen. 



Definition. — Theocorida (vel Tricyi-tida eradiata aperta) with cylindrical 

 abdomen, and wide oj)en truncate mouth. Cephalis with a single horn. 



The genus Theocyrtis and the three following closely allied genera difi"er from the 

 other Theocorida in the cylindrical form of the slender abdomen, which is of equal breadth 

 nearly throughout its whole length. The terminal mouth is wide open, usually truncate, 

 and of the same breadth ; sometimes slightly constricted. The cephalis of Theocyrtis 

 bears a single horn. 



Subgenus 1. Tlieocorypha, Haeckel. 

 Definition. — Pores of the thorax and abdomen of nearly equal size and similar form. 



1. Tlieocyrtis trachelius, Haeckel. 



Eucyrtidium trachelius, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 293, Taf. 

 vii. fig. 8. 



Shell thin-walled and very fragile, smooth. Length of the three joints = 2 : 8 : 7, breadth = 

 2:9:8. Cephalis subspherical, with a straight, conical horn of the same length, separated by a 



1 71ieocyrtis='DiYme basket ; ho;, xvorig. 



