CLYTIA JOHNSTONI. 145 



was usually present. Sometimes, however, as I learn from 

 Dr. Strethill Wright, two or three branches spring from a 

 little below the polypite, and " these secondary stems in 

 like manner give off tertiary stems/' the capsules in such 

 specimens being often axillary. 



The free zooid seems to have been first noticed by Van 

 Beneden, who has figured it in a paper entitled " Un mot 

 sur le Mode de Reproduction des Animaux Inferieurs/' 

 published in 184-7. 



It is a most exquisite organism, about $ of an inch 

 in height at the time of liberation, of graceful form and 

 the purest transparency; its presence is indicated to the 

 naked eye by five opake-white dots, marking the four arms 

 and the manubrium. The perfectly translucent umbrella 

 can only be detected by the aid of a lens. The arms during 

 motion are curled up in several spiral coils, but are capable 

 of great extension. The reproductive sacs are borne on 

 the radiating canals as minute globular enlargements. 

 Each of the lithocysts on the free margin of the umbrella 

 contains a single spherule of carbonate of lime, which is 

 highly refractile. These charming little floating polypites 

 are cast off in immense numbers by the fixed colonies 

 of the Clytia, each freighted with the seed of new ge- 

 nerations; so that we may not wonder at the profuse 

 distribution of the species. M. Lacaze-Duthiers, writing 

 from the neighbourhood of St. Malo, says that he could 

 not take up any water from the sea without meeting with 

 some of them. He was able to observe the ciliated em- 

 bryo, which he describes as resembling a Paramecium in 

 form, and about half a millimetre long. 



The Campanularia Gegenbaurii of Sars (Middelhavet's 

 Litt. Faun. p. 48 ; Gegenbaur, ' Generationswechsel/ pi. i. 

 figs. 1, 2) is perhaps a mere variety of the present species. 



Hob. Extremely common from between tide-marks to 



L 



