1270 THE VOYAGE OF H.M.S. CHALLENGER. 



3. Anthocyrtis butomus, n. sp. 



Shell thorny, with obliterated collar stricture. Length of the two joints = 2:6, breadth = 2:7. 

 Cephalis ovate, with very small and scarce pores, and a conical horn of the same length. Thorax 

 inflated, pear-shaped, with regular, circular, quincuncial pores. Mouth about half as broad, con- 

 stricted, with nine divergent, broad, nearly square, lamellar feet, half as long as the thorax (similar 

 to Anthocyrtis serrulata, Ehrenberg, loc. cit., Taf. vi. fig. 7). 



Dimensions. Cephalis 0'05 long, 0'04 broad; thorax 0'12 long, 0'14 broad. 



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



4. Anthocyrtis ventricosa, Ehrenberg. 



Anthocyrtis ventricosa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. viii. 

 fig. 1. 



Shell thorny, with obliterated collar stricture. Length of the two joints = 1:7, breadth = 

 2 : 7. Cephalis hemispherical, hyaline, without pores, with a slender, conical horn, of about the 

 same length. Thorax inflated, pear-shaped or subspherical, with regular, circular, quincuncial pores. 

 Mouth only one-third as broad, much constricted, with nine divergent, slender, conical feet, about 

 one-fifth as long as the diameter of the shell (partly broken off in Ehrenberg's figure). 



Dimensions. Cephalis 0'03 long, 0'04 broad ; thorax 0'14 long, 0'14 broad. 



Habitat. Tropical Atlantic, Station 338, depth 1990 fathoms ; also fossil in Barbados. 



Subgenus 2. Anthocyrtissa, Haeckel. 



Definition. Feet of the peristome-corona parallel, vertical ; their basal and terminal 

 distances equal. 



5. Anthocyrtis ophirensis, Ehrenberg. 



Anthocijrtis ophirensis, Ehrenberg, 1872, Abhandl. d. k, Akad. d. Wiss. Berlin, p. 285, Tnf. ix. 

 fig. 13. 



Shell smooth, with slight collar stricture. Length of the two joints = 2:4, breadth=l:5. 

 Cephalis ovate, with irregular, roundish pores, and a pyramidal, excentric, vertical horn of the same 

 length. Thorax campanulate, with delicate network of large, regular, hexagonal pores. Mouth 

 scarcely constricted, with nine parallel, vertical, conical feet, about as long as the cephalis. (In the 

 specimen figured by Ehrenberg only seven feet are represented, two being broken off; two other 

 specimens of this species, captured by Eabbe, exhibited nine regularly disposed feet.) 



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



Habitat. Indian Ocean, Zanzibar (Pullen) ; Madagascar (Eabbe), surface. 



