1184 THE VOYAGE OF H.M.S. CHALLENGER. 



2. Cornutanna cyrtoconus, n. sp. 



Shell slender, conical, with curved axis ; the curve lies in one plane as in the similar 

 Cornutella curvata; the pores are smaller and more numerous than in this latter species, and the 

 rounded apex bears no horn. 



Dimensions. Shell 012 to 016 long, 0'05 to 0-07 broad. 



Habitat. South Pacific, Station 300, depth 1375 fathoms. 



3. Cornutanna loxoconus, n. sp. 



Shell wide, conical, with irregularly curved axis ; the parts of the curve do not lie in one plane. 

 Pores very small and numerous, of nearly equal size. 

 Dimeiisions. Shell 0'2 long, 012 broad. 

 Habitat. Tropical Pacific, Station 225, depth 4475 fathoms. 



Genus 528. Archicorys, 1 Haeckel, 1881, Prodronms, p. 427. 



Definition. A rchicorida with simple urceolate or ovate shell, constricted 

 towards the mouth. Apex armed with a horn. 



The genus Archicorys and the following closely allied Cyrtocalpis differ from the 

 two preceding genera in the ovate or urceolate form of the shell, which is more or less 

 constricted towards the terminal mouth. The upper pole in Archicorys bears an apical 

 horn, which is absent in Cyrtocalpis. The origin of these two genera may be the same, 

 probably arising directly fromNassellida, and independently of the triradiate Cyrtoidea 

 or bilocular Spyroidea. (Compare p. 1179.) 



1. Archicorys galea, n. sp. 



Shell smooth urceolate. Pores large, in the middle part hexagonal, towards both ends smaller 

 and polygonal. Apical horn stout, three-sided pyramidal, half as long as the shell. Mouth with a 

 short tubular peristome, about one-third as broad as the shell. 



Z>m7ium&- r -Shell (without horn) 015 long, 012 broad ; horn 0'07 long, mouth 0-05 broad. 



Habitat. Central Pacific, Station 272, depth 2600 fathoms. 



* 



2. Archicorys ampulla, n. sp. 



Shell smooth, thin-walled, bottle-shaped, in the upper half conical, in the lower half inflate, 

 subspherical. Pores subregular, circular, of the same breadth as the bars. Horn conical, stout, 



1 A rchicaryt = Principal helm ; 



