MUSEUM OF COMPARATIVE ZOOLOGY. 295 



New studies must be made to find out whether M. multitentacula and M. nu- 

 tricula are the same species. 



As my identification * of T. nutricula was wrong, my criticisms of McCrady's 

 description of this medusa are unjust to him. The true affinities of the jelly- 

 fish which Mr. Agassiz f and myself J called Turritopsis are somewhat doubt- 

 ful. The " pencil-like clusters of stalked thread-cells " upon the lips allies this 

 medusa to that of Podocoryne carnea, Sars. In a figure f of P. carnea, just 

 escaped from the trophosome, there are eight tentacles, and no rows of lasso- 

 cells extending from the tentacular bulbs to the apex of the bell. The oldest 

 Bpeeimens of C.formosum have more than eight tentacles. It may, however, be 

 simply a more developed planoblast of P. carnea, Sars. 



Ectopleura ochracea, A. Ag. 



rigs. 15, 16, 35, 36. 



The bell of the medusa of K ochracea is high, and has a pointed apex, where 

 its walls are thicker than on the sides. There is no trace of a former tubular 

 connection between the stomach ca\dty and the fixed hydroid through the 

 apex. The outer surface of the bell walls is crossed by eight rows of lasso- 

 cells, which arise in pairs from the tentacular bulbs and have a common junc- 

 tion at the apex of the bell. Near the bulbs the' number of cells in ,each 

 row is larger than towards the apex, where they become more scattered and 

 smaller (?). The chymiferous 'ubes are four Ln number, narrow, and un- 

 branched. 



A manubrium hangs down in the bell cavity about two thirds its height. 

 In normal specimens it is never protruded beyond the bell opening. It is 

 divided into three regions, a basal, median, and terminal. The basal division, 

 by which it arises from the bell walls, is more transparent than the others, and 

 is colorless. It contains many large spherical cells. The remainder of the 

 proboscis has a light rosy color, and is divided midway in its length by a slight 

 constriction, which separates it into a median and a terminal region. Both 

 of these portions are more opaque than the hyaline division with large cells 

 already noticed. Near the region where the junction of the median division 

 with the basal takes place there is a zone of ochraceous colored pigment. The 

 constriction forming the division between the median and terminal divisions is 

 marked by a zone of small dark brown pigment-dots. The lips are thickly 

 pigmented with irregular patches of a yellow color. They bear also, according 

 to Mr. Agassiz, small " bunches of lasso-cells." 



* Bull. Mas. Comp. Zobl., VIII. 7. 



t Op. cit., p. 167. Mr. Agassiz suspected that his medusa was not the same as 

 Turritopsis, McCr., since he was unable to trace it to a medusa of the same form and 

 color. 



t Allman, op. cit., PI. XVI. figs. 3, 4. 



