REPORT ON THE RADIOLARIA. 1303 



with from two to four transverse rows of small, circular pores only. Mouth constricted, with a 

 large cylindrical, tubular, hyaline peristome, half as long as the shell. 



Dimensions. Cephalis 0'03 long, 0'04 broad ; thorax 0'09 long, 0'07 broad. 



Habitat. Western Tropical Pacific, Station 225, depth 4475 fathoms. 



Genus 577. Lophophcena, 1 Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. 



Berlin, p. 54. 



Definition. Sethocorida (vel Dicyrtida eradiata aperta) with ovate or sub- 

 cylindrical thorax, the mouth of which is either truncate or constricted. Cephalis armed 

 with several large horns. 



The genus Lophophcena differs from the nearly allied Sethocorys and Dictyocephalus 

 only in the armature of the large cephalis, which bears a group of large horns, often 

 arranged in a corona of radial spines. Sometimes these spines are connected by 

 anastomosing branches (like Arachnocorys). 



Subgenus 1. Lophophcenula, Haeckel. 



Definition. Horns of the cephalis simple, free, radial spines, neither branched nor 

 connected. 



1 . Lophophcena galea, Ehrenberg. 



Lophophcena galea orci, Ehrenberg, 1854, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 245. 

 Lophophcena apiculata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, 



Taf. viii. fig. 11. 

 1 Cornutella spiniceps, Ehrenberg, 1875J Abbandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. ii. fig. 6. 



Shell with slight collar stricture. Length of the two joints = 5:4, breadth = 5:6. Cephalis 

 subglobular, with numerous bristle-shaped, radial spines, about as long as its radius. Thorax about 

 the same size, truncate, conical, smooth, with wide open mouth. Pores in both joints of equal size, 

 small, regular, circular. 



Dimensions. Cephalis 005 long, 0'05 broad ; thorax O04 long, 0'06 broad. 



Habitat. Tropical Atlantic, Station 348, depth 2450 fathoms ; also fossil in Barbados. 



2. Lophophcena radians, Ehrenberg. 



Lophophcena radians, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, 



Taf. viii. fig. 9. 

 ? Lophophcena lynx, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. viii. fig. 13. 



Shell with slight collar stricture. Length of the two joints = 4:6, breadth = 4:5. Cephalis 

 subglobular, with numerous, stout, conical, radial spines, about as long as its diameter. Thorax 



1 Lophophcena = Shell with a top-knot ; xo'fpoj, 



