1228 THE VOYAGE OF H.M.S. CHALLENGER. 



panulate, twice as broad as the flat mouth, with longitudinal, divergent ribs, alternating with rows 

 of small circular pores. Three feet divergent, striated, gradually lessening from a broad base, twice 

 as long as the thorax, curved like a crescent, with convexity outwards. 



Dimensions. Cephalis 0'02 long, 003 broad ; thorax O06 long, 0'08 broad. 



Habitat. Fossil in Tertiary rocks of Barbados and the Mediterranean (Sicily, Greece). 



13. Lychnocanium fenestratum, n. sp. (PI. 61, fig. 10). 



Shell pear-shaped, rough, with slight collar stricture. Length of the two joints = 1:4, breadth 

 = 1:3. Cephalis subglobular, with a very large prismatic horn, which is about as long as the 

 shell, with three denticulate, prominent, wing-like crests, which are pierced by a series of pores. 

 Thorax ovate, three times as broad as the constricted, prominent mouth, with subregular, circular 

 pores. Three feet arising somewhat above the mouth, prismatic, with denticulate edges, about as long 

 as the thorax, divergent, curved, with convexity outwards. 



Dimensions. Cephalis 0'02 long, 0'03 broad ; thorax 0'08 long, 0'08 broad. 



Habitat. Central Pacific, Station 272, depth 2600 fathoms. 



14. Lychnocanium sigmopodium, n. sp. (PI. 61, fig. 15). 



? Lychnocanium tetrapodium, Ehrenberg, 1875, Abhandl. d. fc. Akad. d. Wiss. Berlin, p. 80, Taf. 

 vii. fig. 3. 



Shell campanulate, rough, with distinct collar stricture. Length of the two joints = 1:4, 

 breadth =1:3. Cephalis subspherical, with a slender, pyramidal horn twice the length. Thorax 

 inflated, conical, with regular, circular pores and a wide open mouth of nearly the same breadth. 

 Three feet widely divergent, twice as long as the thorax, angular, S-shaped, or curved with 

 convexity inwards. (Lychnocanium tetrapodium of Ehrenberg is perhaps a variety of this species ?). 



Dimensions. Cephalis 0'02 long, 0'03 broad; thorax 0'08 long, 0'09 broad. 



Habitat. Cosmopolitan; Mediterranean, Atlantic, Pacific, many stations at various depths ; 

 also fossil in Barbados and Sicily. 



15. Lychnocanium trichopus, Ehrenberg. 



Lychnocanium trichopus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. vii. fig. 5. 



Shell conical, smooth, with deep collar stricture. Length of the two joints =1:3, breadth 

 = 1:3. Cephalis subspherical, with a rudimentary conical horn of half the length. Thorax cam- 

 panulate, with regular, circular pores and wide open mouth of nearly the same breadth. Three feet 

 divergent, very slender, four to five times as long as the thorax, not broader than one pore, S-shaped, 

 or curved with convexity inwards in the distal half. 



Dimensions. Cephalis 0'02 long, O'OS broad ; thorax 0'07 long, 0'09 broad. 



Habitat. Fossil in Barbados. 



