1042 THE VOYAGE OF H.M.S. CHALLENGED. 



Genus 449. Gamospyris,'^ Haeckel, 1881, Prodromus, p. 441. 

 Definition. — Z ygospyrida with two simple lateral feet, forming a ring by union. 



The genus Gamospyris and the similar Stephanospyris differ from all other 

 S p y r o i d e a in the possession of a large basal ring, placed in the frontal plane of the 

 shell. This ring has been produced by concrescence of the distal ends of the two large 

 curved lateral feet of Dipospyris. 



1. Gamospyris circulus, n. sp. (PI. 83, fig. 19). 



Shell subspherical, tuberculate, with subregular circular pores. Basal plate with four larger 

 collar pores. Apical horn pyramidal, about as long as the shell. The connected feet form 

 together a circular or nearly circular smooth ring, the diameter of which is three to four times as 

 great as that of the shell. 



Dimemions. — Shell 0-08 long, O^OO broad ; diameter of the arm-ring 0-25 to 0'33. 



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



2. Gamospyris annulus, n. sp. 



Shell nut-shaped, tuberculate, with subregular circular pores. Basal plate with four large 

 central and a circle of eight to twelve small peripheral pores. Apical horn conical, twice as long as 

 the shell. The connected arms form together an elliptical smooth ring, which is five times as long 

 and three times as broad as the shell. 



Dimensions. — Shell 0'07 long, 0'09 broad ; ring 0'33 long, 0'26 broad. 



Habitat. — Central Pacific, Station 258, depth 2900 fathoms. 



Genus 450. Stephanos2oyris,^ Haeckel, 1881, Prodromus, p. 441. 



Definition. — Z ygospyrida with two lateral feet bearing a series of secondary 

 spines and forming a ring by union. 



The genus Stephanospyris exhibits tlie same peculiar armature of the semipinnate 

 lateral feet as its ancestral genus Dorcadospyris, but differs from it in the concrescence 

 of the distal ends of the feet, to form a complete foot-ring. The former therefore bears 

 to the latter the same relation that Gam,ospyris does to Diposp>yris. 



1. Stephanospyris cordata, n. sp. (PI. 85, fig. 10). 



Shell subspherical, tuberculate, with small regular circular pores. Basal plate with four 

 larger pores. Apical horn cylindrical, three times as long as the shell, with three to four verticils 



1 Gamospi/?-is= Basket with two feet grown together ; ycifto;, gtv^Is. 

 ' Stephanospyris = Basket with a garland ; oTiipeti'of, a-avf^ii. 



