1372 THE VOYAGE OF H.M.S. CHALLENGER. 



4. Alacorys bismarckii, n. sp. (PI. 65, fig. 3). 



Shell spiny, with distinct collar stricture. Length of the three joints =1:4:5, breadth = 

 2 : 7 : 10. Cephalis hemispherical, with a very stout, dimpled, conical horn of the same length. 

 Thorax campanulate, spiny, with regular, circular pores. Abdomen wider, campanulate, with larger 

 conical spines, and a small number of irregular, roundi.sh, very large holes. From the peristome 

 descend, nearly vertically, five very large cylindrical feet, nearly twice as long as the shell ; they are 

 S-shaped, curved, spinulate in the distal half, and armed at the proximal base with two stout 

 conical spines, the smaller of which is directed inwards, the larger curved upwards. Dedicated to 

 Prince Otto von Bismarck, the Eeconstructor of the German Empire. 



Dimensions — Length of the three joints, a 0'02, h 0-08, c 01; breadth, a 0-04, b 014, c 0'2. 



Habitat. — "Western Tropical Pacific (north of New Guinea), Station 220, depth 1100 fathoms. 



Subgenus 3. Hexalacorys, Haeckel, 1881, Prodromus, p. 436. 



Definition. — Peristome armed with six feet, three of which are primary or perradial 

 (Podocyrtis), the three other alternate, secondary or interradial. 



5. Alacorys friderici, n. sp. (PL 65, fig. 1). 



Shell conical, rough, with sharp collar stricture. Cephalis subspherical, with a large, oblique, 

 prismatic horn, twice the length. Thorax campanulate, with regular, circular pores (six to 

 eight in its length). Abdomen wider, campanulate, with a small number of very large pores (three 

 to four in the course of its length). Peristome with six very large divergent feet, which are about 

 as long as the shell, cylindrical, irregularly curved. The specimen figured was observed living, 

 with expanded pseudopodia. The central capsule exhibited four large pear-shaped lobes, filling 

 up the shell-cavity ; each contained an oil-globule in the thoracic part. The undivided cephalic 

 part of the capsule enclosed a nucleus, from which four lobes protruded through the four collar 

 pores into the thorax. Dedicated to Frederick the Great, the Eoyal Philosopher of Potsdam. 



Dimensions. — Length of the three joints, a 0'0.3, h 0'06, c O'OS ; breadth, a 0'04, h 0"09, c 014. 



Habitat. — North Atlantic, Canary Lslands, Lanzerote (Haeckel), surface. 



6. Alacorys guilelmi, n. sp. (PI. 65, fig. 2). 



Shell thorny, with distinct collar stricture. Length of the three joints = 1 : 3:4, breadth = 

 2:5:8. Cephalis hemispherical, with a rudimentary conical horn. Thorax hemispherical, spiny, 

 with regular, cu-cular pores. Abdomen wider, campanulate, i^^piH^te, with a small number of 

 very large circular holes. Peristome with six diverging feet, which are about as long as the shell, 

 at the base conical, thickened, and at the distal end curved inwards, with a spinulate knob. Dedi- 

 cated to the German Emperor, Wilhelm. 



Dimensions. — Length of the three joints, a 0-02, I 0-06, c O'OS ; breadth, a O'OS, b 01, c 016. 



Habitat. — Western Tropical Pacific, Station 224, depth 1850 fathoms. 



