1032 THE VOYAGE OF H.M.S. CHALLENGER. 



as long as the shell. Caudal foot of the same form, twice as long. Two pectoral feet cylindrical, 

 curved, twice as long as the shell, palmate, divided at the distal end into five short fingers. 



Dimensions. — Shell O'OS diameter ; horns 0-04 long ; lateral feet 012 long. 



Habitat. — North Pacific, Station 241, depth 2300 fathoms. 



9. Triceraspyris longicornis, n. sp. 



Shell nut-shaped, papillate, with deep sagittal stricture. Pores irregular roundish. Basal 

 plate with six pores (?). Apical horn short, conical, two frontal horns very large, curved, widely 

 divergent, longer than the shell. Three feet of about the same length, irregularly branched. 



Dimensions. — Shell O'OS long, 0-12 broad ; lateral horns and feet 015 to 0-2 long. 



Sabitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. 



Subgenus 3. Triospyridium, Haeckel. 

 Definition. — Horns and feet forked or branched. 



10. Triceraspyris damaecornis, n. sp. 



Shell nut-shaped, smooth, compressed, with broad sagittal ring. Pores irregular roundish ; one 

 pair of very large pores on each side of the ring. Basal plate with four large coUar pores. Three 

 horns and three feet short, divergent, slightly curved, about half as long as the shell, irregularly 

 branched. (In general form very similar to Maphospyris damaecornis, PI. 84, fig. 10, with which I 

 formerly confounded it.) 



Dimensions. — Shell O'OS long, 012 broad ; horns and feet 0-04 long. 



Habitat. — South Pacific, Station 295, depth 1500 fathoms. 



11. Triceraspyris arhorescens, n. sp. 



SheU subspherical, with deep sagittal stricture. Pores irregular roundish ; three pairs of larger 

 pores on both sides of the ring. Basal plate with two large coUar pores. Three horns about half 

 as long as the shell, with few irregular terminal branches. (Beginning of a cupola.) Three feet 

 strong, cylindrical, twice as long as the shell, richly branched, arborescent. 



Dimensions.— '&\iq\\ 0-09 long, 01 broad ; horns 0'05 long, feet 0'2 long. 



Habitat. — Indian Ocean (Madagascar), Eabbe, surface. 



Genus 443. Tristylospyris^ Haeckel, 1881, Prodromus, p. 441. 

 Definition. — Zygospyrida with three basal feet, without apical horn. 



The genus Tristylospyris exhibits in general the same structure as the typical genus 

 Tripospyris, its ancestral form. It differs from the latter in the absence of the apical 



1 Tristylospyris ='BSi!iket with three styles; r^iarv^o;, a^v^ii. 



