REPORT ON THE RADIOLARIA. 1669 



5. Medusetta tetranema, n. sp. (PI. 120, fig. 3). 



Shell campanulate, conical, smooth, nearly twice as broad as the constricted mouth, without 

 prominent velum. Apical horn somewhat shorter, straight, conical, thorny. Feet strongly curved 

 inwards, convergent, twice as long as the shell, each with four to six strong, ascending, alveolate 

 branches on the abaxial margin. 



Dimensions. Length of the shell 0'07 to 0'09, breadth 0'05 to 0'07. 



Habitat. Tropical Atlantic, Station 352, surface. 



6. Medusetta spiralis, n. sp. 



Shell hemispherical, thorny, with wide open mouth. Apical horn straight, vertical, thorny, 

 twice as long as the shell; feet cylindrical, three times as long as the shell, spirally convoluted around 

 the vertical axis of the shell, with a series of recurved teeth on the abaxial margin. 



Dimensions. Length of the shell 0'05, breadth 0'08. 



Habitat. Central Pacific, Stations 271 to 272, surface. 



7. Medusetta craspedota, n sp (PI. 120, fig. 4). 



Shell campanulate or nearly spherical, spiny, twice as broad as the constricted mouth, which is 

 surrounded by a funnel-shaped truncate velum. Apical horn conical, straight, spiny, half as long 

 as the shell. Feet strongly curved, longer than the shell, with a series of short conical spines on 

 the abaxial side. 



Dimensions. Length of the shell 0'06, breadth O06. 



Habitat.-*- North Pacific, Station 239, surface. 



Genus 701. Euphysetta, 1 n. gen. 



.Definition. M edusettida with four articulate feet on the peristome, one odd 

 very large, and three small or rudimentary feet. 



The genus Euphysetta agrees with the preceding Medusetta in the possession of 

 four articulate feet ; but whilst these in the latter are of equal size and similar shape, 

 in the former a single odd foot only is developed, and very large, whilst the three others 

 are rudimentary and very small. Euphysetta exhibits therefore the same relation to 

 Medusetta that the Euphysidse (Euphysa, Steenstrupia, &c.) bear to the Sarsiadse 

 (Codonium, Sarsia), among the Hydromedusse (compare my System der Medusen, 1879, 

 vol. i. p. 12). 



1 Euphysetta = Diminutive of Euphysa (a Medusa). 



