1404 THE VOYAGE OF H.M.S. CHALLENGER. 



I. Lophoconus antilope, Haeckel. 



Eucyrtidium antilope, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, Taf. ix. 

 fig. 18. 



Shell conical, smooth, with two slight strictures. Length of the three joints = 1:3:8, breadth 

 = 2:4: 8. Cephalis hemispherical, with two divergent, pyramidal horns of twice the length. Thorax 

 campanulate. Ahdomen gradually dilated towards the wide open mouth. Pores very small and 

 numerous, regular, hexagonal. 



Dimensions. Length of the three joints, a O'OIS, I 0'05, c 012 ; breadth, a O025, 5 0'07, c 012. 



Habitat. Indian Ocean ; between Aden and Socotra (Haeckel) ; Zanzibar (Pullen). 



2. Lophoconus hexagonalis, n. sp. 



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

 1 : 2:4, breadth = 1:3:6. Cephalis hemispherical, with numerous conical spines of different 

 sizes, the largest of twice the length. Thorax campanulate, with smaller spines. Abdomen inflated, 

 dilated towards the wide mouth. Pores large, three or four times as broad as the bars, subregular, 

 hexagonal. 



Dimensions. Length of the three joints, a 0'02, b 0'05, c 0'09 ; breadth, a 0'03, I 0'07, c 012. 



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



3. Lophoconus cornutella, n. sp. 



Shell slender, conical, smooth, without external strictures, but with two internal, annular septa. 

 Length of the three joints = 1:2:6, breadth = 1:2:4. Cephalis ovate, with two stout, divergent, 

 conical horns of three times the length. Thorax and abdomen together conical, gradually dilated 

 towards the wide truncate mouth. Pores regular, circular, quincuncial. 



Dimensions. Length of the three joints, a 0'03, 6 O'OS, c 012 ; breadth, a 0'02, 6 0'04, c O'OS. 



Habitat. North Atlantic, Station 353, depth 2965 fathoms. 



4. Lophoconus apiculatus., Haeckel. 



Eucyrtidium apiculatum, Ehrenberg, 1875, AbhandL d. k. Akad. d. "VViss. Berlin, p. 70, 

 Taf. x. fig. 10. 



Shell campanulate, conical, thorny, with two distinct strictures. Length of the three joints = 

 1:2:2, breadth = 1 : 3 : 4. Cephalis subspherical, with a bunch of eight to twelve divergent, conical 

 horns, the largest of which are longer than the cephalis. The regular, circular pores are in the 

 campanulate thorax scarcely half as broad as in the truncate, gradually dilated abdomen. 



Dimensions. Length of the three joints, a 0'02, 6 0'04, c 0'04 ; breadth," a 0'025, 6 0'06, c 0'08. 



Habitat. Fossil in Barbados. 



