1338 THE VOYAGE OF H.M.S. CHALLENGES. 



1. Podocyrtis tnpodiscus, n. sp. (PL 72, fig. 4). 



Shell nearly conical, gradually dilated from the apical to the basal part, with two slight 

 strictures. Surface a little rough. Length of the three joints = 1 : 2:4, breadth = 2:4:6. Pores 

 subregular, circular, quincuncially disposed, of nearly equal size in the conical thorax and the 

 subspherical abdomen. Cephalis hemispherical, with smaller pores and a spindle-shaped spiny 

 horn of twice the length. Feet cylindrical, as long as the abdomen, little divergent, their ends 

 curved outwards and thickened into a papillate knob. 



Dimensions. Length of the three joints, a 0'02, b 0'03, c O08 ; breadth, a 0'03, I 0'07, c Oil. 



Habitat. Central Pacific, Station 265 to 272, depth 2425 to 2925 fathoms. 



2. Podocyrtis attenuata, Ehrenberg. 



Podocyrtis attenuata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xvi. fig. 5. 



Shell nearly conical, gradually dilated from the apical to the basal part, with two slight 

 strictures. Surface a little rough. Length of the three joints = 2 : 3 : 4, breadth = 2: 4: 5. Pores 

 subregular, circular, equal, quincuncial. Cephalis subspherical, with a conical horn of twice the 

 length. Feet cylindrical, as long as the abdomen, little divergent (sometimes as in the specimen 

 figured, nearly parallel). 



Dimensions. Length of the three joints, a 0'015, b 0'03, c 0'04 ; breadth, a 0'02, b 0'04, c 0'05. 



Habitat. Fossil in Barbados. 



3. Podocyrtis thyrsoceras, n. sp. 



Shell slender, conical, smooth, very similar to Thyrsocyrtis rhizodon, Ehrenberg (1875, Abhandl. 

 d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xii. fig. 1), with two slight strictures, nearly of the same 

 form and fenestration as in the preceding smaller species. Length of the three joints = 1:2: 3, 

 breadth = 1 : 3:4. Cephalis subspherical, with a large cylindrical straight horn, which reaches the 

 length of the abdomen, and is papillate in the distal half. Feet cylindrical, divergent, nearly as 

 long as the whole shell, broadened and spinulated at the distal end. 



Dimensions. Length of the three joints, a 0'02, b 0'04, c OD6 ; breadth, a O02, b 0'06, c 0'08. 



Habitat. South Pacific, Station 295, depth 1500 fathoms. 



4. Podocyrtis conica, n. sp. 



Shell conical, without external strictures, but with two internal septal rings , Surface papillate. 

 Length of the three joints = 2:3: 8, breadth = 3:6: 10. Pores equal, subregular, circular, 

 quincuncial. Cephalis hemispherical, with a thick conical horn of the same length. Feet conical, 

 about as long as the thorax, divergent in the direction of the outline of the conical shell. 



Dimensions. Length of the three joints, a 0'02, b 0'03, c 0'08 ; breadth, a 00'3, b 0'06, c 01. 



Habitat. Cosmopolitan, Central Pacific, Stations 263 to 274 ; Tropical Atlantic, Station 348, 

 in depths between 2350 and 2925 fathoms ; also fossil in Barbados. 



