REPORT ON THE RADIOLARIA. 1667 



Genus 699. Cortinetta^ n. gen. 

 Definition. M edusettida with three articulate feet on the peristome. 



The genus Cortinetla comprises those Medusettida which exhibit the minimum 

 number of feet, three, and which therefore may be compared to the tripodal NASSELLARIA 

 (Cortina, Cortiniscus, Tripodiscus, &c.). This similarity is the greater, as in the few 

 observed species an apical horn is developed (as also in the following genus). The 

 three feet are in the two species observed of equal size and similar form, and equidistant, 

 so that they cannot be distinguished as an odd caudal and two paired lateral feet, as 

 in the similar NASSELLARIA. 



1. Cortinetta tripodiscus, n. sp. (PI. 117, fig. 7). 



Shell campanulate, covered with numerous curved ascending bristles, with a prominent annular 

 velum on the peristome, similar to that of Medusetta craspedota (PI. 120, fig. 4). Feet equal, widely 

 divergent and equidistant, somewhat longer than the shell, slightly curved, and covered on their 

 convex outer edge with a series of short lateral branches, the three ramules of which bear a spathilla. 

 Apical horn conical, straight, about as long as the shell, also covered with curved bristles. 



Dimensions. Length of the shell 014, breadth Oil; length of the feet 016, of the apical 

 horn Oil. 



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



2. Cortinetta cortiniscus, n. sp. 



Shell campanulate, subspherical, thorny, with a prominent annular velum on the peristome. 

 Feet equal, very large, widely divergent, about three times as long as the shell and studded with 

 arborescent branches, similar to those of Gfazellctta drymonema (PL 118, fig. 1). Apical horn slender, 

 conical, straight, thorny, twice as long as the shell. 



Dimensions. Length of the shell 018, breadth 016 ; length of the feet 0'5 to 0'6, of the 

 apical horn 0'33. 



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



Genus 700. Medusetta? n. gen. 



Definition. M edusettida with four equidistant articulate feet of equal size 

 on the peristome. 



The genus Medusetta comprises those forms of the family which bear on the 

 peristome four equal radial feet, and therefore exhibit a striking similarity to many 



1 Cortinetta, Diminutive of Cortina. 2 Medusetta = Small Medusa. 



