28 PODOCORYNIDyE. 



set placed at the termination of the canals, the number 

 increasing with age, and always a multiple of four. 



THE Dysmorphosa of Philippi is undoubtedly identical 

 with Podocoryne, and his name has precedence in point of 

 time. As, however, Sars's genus must be broken up into 

 two sections (the one including the species in which the 

 sexual zooids become free, the other those in which they 

 continue fixed), both names may be retained. I have 

 assigned Podocoryne to the former of these divisions, of 

 which the well-known P. carnea may be taken as the type. 

 The other should bear Philippics name *. 



Under P. carnea an account is given of the mode in which 

 the common crust is developed in this genus. The early and 

 the later states are so different that they would probably be 

 referred to distinct genera if the intermediate stages of 

 growth had not been observed. 



Krohn has described the budding of young from the 

 manubrium of the free sexual zooid, and A. Agassiz has 

 made similar observations on an allied species (Dysmor- 

 phosa fulgurans}. Development takes place with great 

 rapidity, and "buds of the third generation are already 

 forming while the second is still attached." 



Agassiz mentions that the latter species is sometimes so 

 abundant that the whole sea, when disturbed, is brilliantly 

 lighted by the peculiar bluish phosphorescent colour which 

 it gives out f. We cease to wonder at the amazing num- 

 ber of these (so-called) Medusae when we know that thev 

 are not only thrown off by hundreds from each densely 

 packed hydroid colony, but that every one of them has the 

 power of producing a family by gemmation. 



* Allman has proposed the name Stylactis for this section. But as he 

 now recognizes the identity of Dysmorphosa and Podocoryne, he will pro- 

 bably not deem it desirable to displace either of the older names. 



t Catal. of North American Acalephw, p. 163. 



