1038 THE VOYAGE OF H.M.S. CHALLENGER. 



relation to that which the hornless Tristylospyris, among the Tripospyrida, bears to the 

 horned Tripospyris. Brachiospyris may therefore also be derived from Tristylospyris 

 by loss of the caudal foot. 



1. Brachiospyris ocellata, Haeckel. 



Ceratospyris ocellata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xx 

 fig. 5. 



Shell nut-shaped, thorny, with slight sagittal stricture and irregular roundish pores. Basal 

 plate with four large and four .alternate pairs of smaller pores. Two feet cylindrical, straight, 

 divergent, two to three times as long as the shell. 



Dimensions. Shell 0'08 long, Oil broad: feet 0'2 to 0'3 long. 



Habitat. South Atlantic, Station 335, depth 1425 fathoms ; also fossil in Barbados. 



2. Brachiospyris diacantha, n. sp. (PI. 95, fig. 5). 



? Ceratospyris diacantha, Ehrenberg, 1872, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 303. 



Shell nut-shaped, tuberculate, compressed in the sagittal axis, convex on the frontal face, concave 

 on the sagittal face, with a slight sagittal stricture ; with large irregular roundish pores. Basal 

 plate with three very large pores. Two feet cylindrical, curved, S-shaped, about twice as long as 

 the shell. 



Dimensions. Shell 0'06 long, 0'09 broad ; feet 01 to 015 long. 



Habitat. Western Tropical Pacific (Philippine Sea), Station 206, depth 2100 fathoms. 



Genus 447. Dendrospyris, 1 Haeckel, 1881, Prodromus, p. 441. 



Definition. Z ygospyrida with two free lateral feet, forked or branched like 

 a tree. Apex with a horn. 



The genus Dendrospyris differs from its ancestral form Dipo^yris in the 

 ramification of the two large lateral feet, which descend from the base of the shell, and 

 are usually very large and stout, sometimes simply forked. 



1. Dendrospyris stylophora, Haeckel. 



Ceratospyris stylophora, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xx. 

 fig. 10. 



Shell nut-shaped, thorny, with subregular circular pores. Basal plate with four pores. Apical 

 horn and the two divergent feet straight, cylindrical, larger than the shell, forked at the distal end. 



1 Dendrospyris -- Basket with arborescent feet ; aii/toon, ovvgls. 



