1082 THE VOYAGE OF H.M.S. CHALLENGER. 



size. Apical horn pyramidal, about as long as the shell. Basal coronet with twenty to twenty- 

 five slender, lamellar, pointed, vertical feet, longer than the shell. 



Dimensions. Shell Oil long, 012 broad ; ring 0'07 long; horn 01 ; feet 012 to 018 long. 



Habitat. Central Pacific, Station 268, depth 2900 fathoms. 



Genus 472. Tiarospyris, 1 Haeckel, 1881, Prodromus, p. 443. 



.Definition. Thol o spy r ida with numerous basal feet (eight to twelve or 

 more). Galea without a horn. 



The genus Tiarospyris has probably been derived from the preceding Sepalospyris 

 by reduction and loss of the free apical horn ; it therefore bears to it the same 

 relation that the similar Gorgospyris does to Petalospyris. 



1. Tiarospyris pervia, n. sp. (PL 87, fig. 7). 



Shell nut-shaped, smooth, with deep sagittal stricture. Cephalis on the lateral sides with 

 numerous small roundish pores, on each side of the ring with a pair of very large holes. Basal 

 plate with two large collar pores. Cupola flat, cap-shaped, with two large parietal pores above 

 the ring. Coronet with eight conical, slightly divergent feet, about one-fourth as long as the shell. 



Dimensions. Shell 0'08 long, 01 broad ; ring 0'06 long ; feet 0'02 long. 



Habitat. North Pacific, Station 244, depth 2900 fathoms. 



2. Tiarospyris galea, n. sp. 



Shell helmet-shaped, with deep sagittal stricture. Cephalis with irregular, polygonal pores ; on 

 each side of the ring two pairs of larger annular pores. Basal plate with four large pores. 

 Cupola high, conical, nearly as long as the cephalis, separated from it by a distinct coronal 

 stricture. Basal coronet with twelve to sixteen slender curved divergent feet, nearly as long as 

 the shell. 



Dimensions. Shell 016 long, 012 broad; ring 01 long; feet 015 long. 



Habitat. Central Pacific, Station 265, depth 2900 fathoms. 



3. Tiarospyris mitra, n. sp. (PL 87, figs. 9, 10). 



Shell subspherical, smooth. Cephalis on the lateral sides with small roundish, double- 

 contoured pores, on each side of the ring with three to five pairs of larger pores, each of which 

 is closed by a thin fenestrated lamella (different on the frontal face, fig. 9, and the dorsal face, 

 fig. 10). Cupola flat, cap-shaped, separated by a distinct coronal stricture, with smaller pores. 

 Basal coronet with ten to twelve short conical convergent feet. 



Dimensions. Shell Oil long, 012 broad; ring 0'04 long; feet 0'02 long. 



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



1 Tiarospyris Basket with a cap ; 



