1080 THE VOYAGE OF H.M.S. CHALLENGER. 



bearing an irregularly branched horn. Caudal foot short conical, simple. Two pectoral feet half as 

 long as the shell, angular, subvertical, irregularly branched. 



Dimensions, Shell 015 diameter, ring 01 long, pectoral feet 0'07 long. 



Habitat. Central Pacific, Station.271, depth 2425 fathoms. 



5. Tholospyris cupola, n. sp. (PL 89, fig. 4). 



Shell pear-shaped or cupola-shaped, smooth, with slight sagittal stricture. Cephalis not 

 distinctly separated from the galea, as the ring in the uppermost part of the shell- wall becomes 

 obliterated. Pores irregularly polygonal, small and numerous. Basal plate with four large pores. 

 Apical horn and the three divergent feet, irregularly branched ; feet nearly as long as the shell, 

 about four times as long as the horn. 



Dimensions. Shell 014 diameter, ring 01 long, feet 012 long. 



Habitat. Central Pacific, Station 274, depth 2750 fathoms. 



Genus 470. Lophospyris, 1 Haeckel, 1881, Prodromus, p. 443 (sensu emendato). 

 Definition. T holospyrida with two lateral basal feet and an apical horn. 



The genus Lophospyris differs from the preceding TJwlospyris, its probable ancestral 

 form, in the absence of the caudal foot, and therefore bears to it the same relation that 

 Dipospyris does to Tripospyris. The two pectoral feet are alone developed and are 

 placed opposite in the frontal plane. Lophospyris may also be derived from Dipospyris 

 by the formation of a galea. 



1. Lophospyris dipodiscus, n. sp. (PL 95, fig. 14). 



Shell ovate, spinulate, with sharp transverse coronal constriction. Cupola hemispherical, half as 

 large as the nut-shaped cephalis. Pores irregularly roundish, much larger on the sagittal constriction. 

 Apical horn pyramidal, about half as long as the shell. Two lateral feet cylindrical, strongly 

 curved, about as long as the shell, with some irregular branches ; together forming a nearly 

 complete circle. 



Dimensions. Shell 0'09 long, 0'08 broad; ring 0'04 long, feet 0'08 long. 



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



\ 



2. Lophospyris acuminata, Haeckel. 



Ceratogpyris acuminata, K. Hertwig, 1879, Organism, d. Kadiol., p. 70, Taf. vii. fig. 2. 



Shell campanulate, smooth, without external transverse stricture. Cupola conical, half as long 

 and broad as the nut-shaped cephalis. Pores irregularly roundish, on each side of the sagittal 



1 Lophospyris = Basket with a crest ; Ao'Tof, aicutf;. 



