216 M. B. Uljanin on the Btiddiay of the Ciiniiuy. 



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firm conviction that the Cunince which sprout in the stomach 

 of the Geryonidse are nothing hut parasites of the Carmarinw] 

 but I could not manage to rear the young Cunince up to their 

 full sexual maturity and to refer them to their parent form. 



In what follows I briefly sum up the principal results of 

 my investigations, and will hereafter publish a more detailed 

 account of my observations elsewhere. 



The youngest stage observed by me (fig. 1) is a larva 

 measuring 0'17-0*25 millim., the body of which consists of a 

 one-layered ectoderm and entoderm. 

 The two layers pass over into one 

 another, and bound a cavity which 

 opens outwards by an orifice and is 

 almost entirely occupied by a finely 

 granular mass (^^r), which may some- 

 times be protruded a little from the 

 orifice during the rather strong con- 

 tractions of the larva. I have several times fished larvae of 

 the same structure with the muslin net from the sea at Villa- 

 franca, but have still more frequently met with them (some- 

 times in great abundance) in the stomach and radial canals of 

 Carmarina has fata. 



With the grov.?th of the larva the cells, both of the ecto- 

 and entoderm, are multiplied. In consequence of the much 

 more rapid growth of the ectoderm, the entoderm splits into 

 two layers, between which a cavity (the body-cavity of the 

 polype) then becomes perceptible. The young animal, which 

 still moves freely in the stomach 

 and radial canals of the .Carma- 

 rina by means of its ciliary coat 

 (it is shown in longitudinal section 

 in fig. 2), consists of the finely 

 granular mass {Pr), which is sur- 

 rounded by a series of cells (en^), 

 the lower layer of the split ento- 

 derm, and of the ectoderm {ec) 

 with the upper layer of the 

 split entoderm (en^), by which 

 the body-cavity (h) of the polype 

 is bounded. 



Soon after the cleavage of the entoderm of the larva and 

 the formation of the cavity of the polype {h) between the two 

 resulting entodermal layers, the short teutaculiform excrescences 

 which serve to attach the young polype-stock to the Carma- 

 rina begin to sprout round the orifice of the mouth. Both 

 body-layers of the polype take part in the formation of these 



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