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



6. Dendrocircus barbadensis, n. sp. 



Gate irregularly ovate or nearly semicircular. King of the same oblique form, thick, with 

 interrupted and distorted edges, armed with eight to twelve larger irregularly formed and branched 

 acute spines ; between them numerous conical smaller spines. This common species is very 

 polymorphous and variable. 



Dimensions. Diameter of the ring 0'05 to 0'08 ; length of the spines O'OOS to 0'02. 



Habitat. Fossil in Barbados. 



7. Dendrocircus stalactites, n. sp. (PL 81, fig. 14). 



Gate obliquely ovate. King irregularly ovate or roundish, very thick, without edges, armed with 

 numerous (eight to twelve or more) short and stout branches, which are shorter than the diameter 

 of the gate, irregularly disposed and branched, with very numerous clustered blunt ramules. 



Dimensions. Diameter of the gate 0'07 to 0'09 ; length of the spines 0'02 to 0'06. 



Habitat. Western Tropical Pacific, Station 225, depth 44*75 fathoms. 



Subfamily 2. CORTINIDA, Haeckel. 

 Definition. S tephanida with typical basal feet (or cortinar feet).- 



Genus 405. Cortina, 1 n. gen. 



Definition, S tephanida with a simple dipleuric or bilateral ring, bearing at 

 the base three divergent feet (one odd caudal and two paired lateral feet). 



The genus Cortina, and the following Stcphanium represent together the small but 

 very important group of Cortinida, differing from the simple Lithocircida in the 

 possession of three typical basal feet, which are transmitted to the majority of the 

 NASSELLARIA by heredity, and produce their peculiar triradial structure. They appear 

 therefore as a combination of the simple ring (Zygocircus) with three basal feet 

 (Plagonium). One of these three divergent feet is the odd caudal foot, opposite 

 to the apical horn ; the two others are the paired lateral or pectoral feet. (On the 

 probable origin and the typical signification of Cortina compare above, pp. 891894.) 



.1.- Cortina tripus, n. sp. (PI. 83, fig. 9). 



.King ovate, smooth, or with a few short thorns. Apical horn oblique, curved, simple, smooth, 

 about as long as the sagittal axis of the ring. Feet divergent, curved, simple, smooth, about as 



1 Cortina = Tripod. 



