1222 THE VOYAGE OF H.M.S. CHALLENGER. 



3. Eucecryphalus cuvieri, n. sp. 



Shell flatly conical, with slight collar stricture. Length of the two joints = 1:8, breadth = 2:10. 

 Cephalis hemispherical, with an oblique pyramidal horn twice as long. Thorax with straight 

 outlines and regular hexagonal meshes, increasing in size towards the mouth. From the collar 

 stricture there arise three stout conical spines, half as long as the thorax, and diverging downwards. 

 Peristome with a ring of small square pores and alternate conical divergent spines. Differs from 

 the similar Clathrocyclas alcmence (PL 59, fig. 6), mainly in the simple apical horn and the possession 

 of the three collar fundamental spines. 



Dimensions. Cephalis O02 long, 0'03 broad ; thorax 015 long, 0'2 broad. 



Habitat. Tropical Atlantic, Station 342, depth 1445 .fathoms. 



4. Eucecryphalus mulleri, n. sp. 



Shell flatly campanulate, of nearly the same structure as and similar form to that of the preceding 

 species. Differs from it mainly in the considerable size of the cephalic horn and the three collar spines, 

 which are bristle-shaped and longer than the shell. Length of the two joints =1:4, breadth = 

 2 : 8. The peristome bears a double marginal ring of divergent conical spines, the upper being 

 directed upwards, the lower downwards. 



Dimensions : Cephalis 0'02 long, O04 broad ; thorax 0'08 long, 016 broad. 



Habitat. North Pacific, Station 241, depth 2300 fathoms. 



.5. Eucecryphalus gegenbauri, Haeckel. 



Eucecryphalus gegenlauri, Haeckel, 1862, Monogr. d. Radiol., p. 308, Taf. r. figs. 12-15. 

 Eucecryphalus gegenbauri, R. Hertwig, 1879, Organism, d. Radiol., p. 76, Taf. viii. figs. 5, 

 :5a, 56. 



Shell flatly conical, campanulate, with slight collar stricture. Length of the two joints = 1 : 4, 

 breadth = 1:8. Cephalis .hemispherical, with a conical horn of the same length, and very small 

 pores.' Thorax about twice as broad as high, with large, subregular, hexagonal meshes, increasing in 

 size downwards. In the upper half of the thorax the meshes are filled up by an extremely delicate 

 arachnoidal network. From the collar stricture there arise three divergent bristle-shaped spines half 

 as long as the thorax. Peristome with a double coronal of small square pores (the inner smaller and 

 more numerous than the outer), and with a single coronal of divergent marginal spines. This 

 cosmopolitan species is rather variable. 



Dimensions. Cephalis 0"02 to 0'03 diameter; thorax 01 to 012 long, 0'02 to 0'25 broad. 



Habitat. Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface. 



