REPORT ON THE EADIOLARIA. 1301 



8. Sethocyrtis cassis, Haeckel. 



Cuniutdla casng, Ehrenborg, 1834, Mikrogeol., Taf. xxii. fig. 38. 

 CyHocalpis cassis, Haeckel, 1862, Monogr. d. Eadiol., p. 287. 



Shell pear-shaped, smooth, with obliterated collar stricture. Length of the two joints = 4 : 13, 

 breadth = 3 : 12. Cephalis ovate, with a conical horn of half the length. Thorax inflate, ovate, 

 with subregular, circular, quiucuncial pores, twice to three times as broad as the bars. Mouth con- 

 stricted, truncate, two-thirds as broad as the thorax, without prominent peristome. 



Dimensions. — Cephalis 0'04 long, 0"03 broad ; thorax 013 long, 012 broad. 



Habitat. — Fossil in Tertiary rocks of Sicily (Caltanisetta). 



Genus 576. SetJiocorys,^ Haeckel, 1881, Prodromus, p. 430. 



Definition. — Se t h o c o ri dii (vel Dicyrtida eradiata aperta) with ovate or sub- 

 cyKndrical thorax, the mouth of which is constricted and prolonged into a ring-like 

 peristome. Cephalis with an apical horn. 



The genus Scthocorys differs from the preceding Sethocyrtis, its ancestral form, 

 in the form of the constricted mouth, which is prolonged into a prominent, hyaline, 

 tubular, or annular peristome. 



1. Sethocorys achiUis, u. sp. (PI. 62, fig. 8). 



Shell rough, pear-shaped, with distinct collar stricture. Length of the two joints = 4 : 8, 

 breadth = 3:8. Cephalis ovate, with a stout pyramidal horn of half the length. Thorax nearly 

 spherical, with regular, circular, quincuncial pores of the same breadth as the cephalic pores. 

 Mouth constricted, half as broad as the thorax, with a broad, smooth, striated peristome. 



Dimensions. — Cephalis 0'04 long, 0'03 broad ; thorax 0'08 long, O'OS broad. 



Mahitat. — Cosmopolitan ; Mediterranean (Corfu), Atlantic, Indian, Pacific ; many stations, at 

 various depths. 



2. Sethocorys patrocli, n. sp. 



Shell thorny, pear-shaped, with slight collar stricture. Length of the two joints = 4 : 12, 

 breadth = 3 : 10. CephaHs ovate, with a pyramidal horn of twice the length. Thorax ovate, 

 truncate at both poles, with regular, circular pores, twice as broad as the cephalic pores. Mouth 

 constricted, half as broad as the thorax, with a broad, smooth, prominent peristome. 



Dimensions. — Cephalis 0'04 long, 0'03 broad ; thorax 012 long, 01 broad. 



Halitat. — Central Pacific, Stations 2G3 to 274, depth 2350 to 3000 fathoms. 



1 Rethocorys -- Sieve-helmet ; ciidu, xoov;. 



