L.M.B.C. MEDUSAE. 281 



ginal vesicles between every two tentacles, with a single 

 otolith in each. Stomach very short, and mouth with 

 four lips. Eeproductive organs occupying the lower half 

 of the four radial canals, and slightly folded into a longi- 

 tudinal wavy line. Tentacle-bulbs and reproductive 

 organs yellowish brown. 



The second specimen taken on May 9th. Umbrella 11 

 mm. long and 21 mm. wide. 38 tentacles, ten in three 

 of the quadrants, and eight in the other. Two or three 

 marginal vesicles between every two tentacles with a 

 single otolith in each. Eeproductive organs occupying 

 the lower half of the radial canals. Tentacle-bulbs and 

 reproductive organs yellowish brown. 



On May 19th, 1893, I took a medusa in Port Erin Bay 

 which I also believe to be Phialidium variabile. Um- 

 brella about 9 mm. long and 12 mm. wide. 32 tentacles, 

 nine in two of the quadrants, and seven in the other two, 

 a single marginal vesicle between every two tentacles, 

 with a single otolith in each. Eeproductive organs 

 occupying the lower half of the four radial canals, long 

 and oval in shape, and of pale greenish colour. Tentacle- 

 bulbs yellowish. This medusa corresponds with Forbes's 

 description and figure of Thaumantias inconspicua which 

 appears to be a somewhat earlier stage, about 18 mm. in 

 width, 16 — 20 tentacles and between each pair "a rudi- 

 mentary marginal tubercle" (marginal vesicle). Ovaries 

 long and linear, and of a faint lilac or greenish hue, 

 occupying more than half the length of each radial canal. 

 Tentacle-bulbs yellowish. Haeckel, however, regards 

 Thaumantias inconspicita, Forbes, as a stage of Thauman- 

 tias hemisphcerica, Eschscholtz ( = T. hemisphcerica, 

 Forbes). Haeckel has placed T. hemisphcerica amongst 

 the Thaumantidce a family distinguished by the absence 

 of marginal vesicles. M'Intosh (17) appears to regard 



