

L.M.B.C. MEDUSiE. 257 



The young medusa Hybocodon prolifer has all the charac- 

 teristic features of the medusa, Ampliicodon fritillaria. 

 The shape of the umbrella, the five rows of nematocysts, 

 and the budding of medusa from the base of the large 

 tentacle are common to both. The young hydroids 

 which I reared at Port Erin have every appearance of 

 becoming similar to the hydroid taken by Agassiz. 

 They agree in colour, in the longitudinal striae of the 

 stem formed by the coenosarc, and the tentacles of the 

 posterior verticil are about the same in number. The 

 anterior verticil has only eight tentacles, but others may 

 appear as the head grows larger. The discovery of the 

 adult hydroid with medusae on the Manx coast will settle 

 the identity at once. 



, Bohni (Jena zeitschr. f. Naturw., Vol, XII, 1878) 

 captured a specimen of a medusa off Heligoland which 

 he believed to be identical with the American Hybocodon 

 prolifer. The medusa has two tentacles on the large 

 tentacle-bulb on the longest side of the umbrella and 

 many medusa-buds, and also the five rows of nematocysts 

 on the umbrella. Haeckel however, places Hybocodon 

 prolifer of Bohm as a synonym of Ampliicodon fritillaria. 



In the last Annual Beport (1894) of the L.M.B.C, it 

 is stated on my authority that Ampliicodon fritillaria is 

 an addition to the fauna of the British seas, but I have 

 recently read a paper by Mr. J. K. Green (13) on the 

 medusae on the coast of Dublin in which he clearly 

 describes specimens of Ampliicodon fritillaria found on 

 that coast about 1856. He describes them as two new 

 species — Diplonema islandica and Steenstrupia owenii. 



Diplonema islandica, has two tentacles on the large 

 bulb on the longest side of the umbrella. Tentacle-bulbs 

 of a brilliant crimson colour. A medusa-bud on the large 

 tentacle-bulb, and in one specimen a medusa-bud on one 



