helonghig to the Family Laodiceidse. 459 



the cordylus. On the development of the bud into a bulb the 

 cirrus and cordylus were carried up on to the side of the 

 bulb. It is rare to find a cirrus and cordylus on the side of 

 a basal bulb of a large tentacle, so that these organs either 

 change their position or disappear. They cannot develop into 

 a tentacle, because the tentacle is already formed. 



In the two specimens showing the cordyli being converted 

 into tentacles it was fairly evident that the tentacular bud 

 made its appearance right underneath the already fully deve- 

 loped cordylus. There were a sufficient number of bulbs with 

 cordyli to trace out the various stages of growth. One bulb 

 showed very distinctly the conical apex of the sprouting 

 tentacle beneath the translucent stalk of a cordylus, and later 

 stages showed the translucent cells of the cordyli becoming 

 opaque as the tentacles advanced in size. The cordylus in 

 the process of conversion becomes very large, and finally 

 loses its characteristic shape. It seems to me that the cells 

 of the cordylus are converted into tentacular cells, and as 

 soon as that process is completed the rounded end of the 

 cordylus becomes pointed and indistinguishable from an 

 ordinary half-grown tentacle. 



As the conversion of cordyli into tentacles was only seen in 

 two young stages, it is probably due to the cordyli being in 

 the way of rapidly growing tentacles, and consequently they 

 were absorbed. 



A time comes when tentacular growth stops and the bulbs 

 remain in an arrested state of development. This, I think, 

 accounts for some adult specimens having their cordyli upon 

 small bulbs and also upon bulbs with ocelli. 



Family LaodiceidaB, L. Agassiz, 1862. 



Character of the Family. — Leptomedusfe with cordyli, 

 commonly called sensory clubs, on the margin of the 

 umbrella. 



Genus Laodice, Lesson, 1843. 



Oenertc character. — Laodiceidie with four radial canals ; 

 with a central stomach and mouth ; with ocelli on the basal 

 bulbs of the tentacles. 



This is the best-known gonus of the family. Although I 

 have excluded several species which were formerly placed in 

 the genus and reduced others to synonyms, still I am not 

 quite satisfied with the result, owing to the difficulty of 



ao* 



