1344 THE VOYAGE OF H.M.S. CHALLENGER. 



with four to five transverse rows of very large, subregular, hexagonal pores. Feet short and thick, 

 bent outwards, as long as the thorax. 



Dimensions. Length of the three joints, a 0'025, b 0'05, c 015 ; breadth, a 0'05, b 01, c 013. 



Habitat. Central Pacific, Station 265, depth 2900 fathoms ; fossil in Barbados. 



24. Podocyrtis ehrenbergii, Haeckel. 



Podocyrtis ampMacantha, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. 



xvii. fig. 3. 



Shell slender, ovate, smooth, with deep collar, but evanescent lumbar stricture. Length of the 

 three joints = 1:3:2, breadth = 1:3:3. Cephalis subspherical, with a large conical horn, as long 

 as the campanulate thorax. Abdomen nearly cylindrical. Pores irregular, roundish, two to four 

 times as large in the abdomen as in the thorax. Feet conical, slender, divergent, nearly as long as 

 the shell. (In the imperfect specimen figured by Ehrenberg, two spines were broken off.) 



Dimensions. Length of the three joints, a 0'02, I 0'06, c 0'04 ; breadth, a 0'02, b 0'06, c 0'06. 



Habitat. North Pacific, Station 253, depth 3125 fathoms ; fossil in Barbados. 



25. Podocyrtis argulus, Ehrenberg. 



Podocyrtis argulus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xvi. fig. 2. 



Shell slender, ovate, or subconical, with two deep strictures. Length of the three joints = 

 1:2:4, breadth = 1:3:4. Cephalis hemispherical, with a small conical horn of the same length 

 (broken off in the figure of Ehrenberg). Pores regular, circular, three times as broad in the inflated 

 abdomen as in the campanulate thorax. Feet spindle-shaped, slender, divergent, about as long as 

 the thorax. 



Dimensions. Length of the three joints, a 0'025, b 0'05, c 01 ; breadth, a 0'03, b 0'07, c 01. 



Habitat. Tropical Atlantic, Station 247, depth 2530 fathoms ; also fossil in Barbados. 



Subgenus 3. Podocyrtidium, Haeckel. 



Definition. Feet convergent (the distance between their ends being smaller than 

 that between their bases). Pores of the thorax and abdomen nearly equal in size and 

 similar in form. 



26. Podocyrtis papalis, Ehrenberg. 



Podocyrtis papalis, Ehrenberg, Mikrogeol., Taf. xxxvi. fig. 23 ; Abhandl. d. k. Akad. d. 

 Wiss. Berlin, 1875, p. 82, Taf. xv. fig. 6. 



Shell ovate, smooth, without external stricture. Length of the three joints = 1:3:1, 

 breadth = 1:3:3. Cephalis ovate, with a stout pyramidal horn of twice the length. Thorax and 



