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



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

 horned Tripospyris. Brxicliiospyris may therefore also be derived from Tristylosjyyris 

 by loss of the caudal foot. 



1. Brachiospyris oceUata, Haeckel. 



Cefatospyris ocellata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Bei'lin, p. 66, Taf. xx. 

 fig. 5. 



Shell iiut-shaped, thorny, with slight sagittal stricture aud irregular roundish pores. Basal 

 plate with four large aud 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 diaeantha, u. sp. (PI. 95, tig. 5). 



1 Ceratospyris diaeantha, 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. 



Hahitat. — Western Tropical Pacific (Philippine Sea), Station 206, depth 21(J0 fathoms. 



Genus 447. Dendrospyris,^ 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 Dipospyris 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 styloj/hora, 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 sliell, forked" at the distal end. 



1 Dendrospyris - Basket with arborescent feet ; osj/Sjok, owi/j iV. 



