MELIC'EHTLM C AMl'AN LLA. 



131 



Vie- 202. 



observed on the coast of New England. Undoubtedly a few others of 

 the Jelly-fishes he has enuinerated will prove identical with species 

 since described, on the coast of England and on our own shores. A 

 Medusa of this same genus was figured and described by Forbes under 

 the name of Sfomohrachium ocfocostatum ; from the figure of Forbes 

 it is evidently not a Stomobrachium, and is probably this same Medusa 

 which he found in the North of Scotland. Fig. 202 is a profile view, 

 natural size, of the Melicertum, one of the most common of our naked- 

 eyed Medusae. In the foil, at the time of spawning, it literally swarms 

 at the surfiice, and on sunny days seems particularly to delight to 

 come to the surfiice, where it remains in the afternoon until dark, 

 being one of the few Medusae 

 {Ziigodactiila groenlandica has 

 the same habit) which are to 

 be met with in the after- 

 noon. The genus Melicertum 

 is closely related to the /Equo- 

 rida^, by the number of its 

 radiating tubes (of which there 

 are eight), and to Staurophora, 

 by the blending of the genital 

 organs with the actinostome, 

 and the total absence of mar- 

 ginal bodies, such as capsules, 

 cirri, and so forth. If the 

 small Medusae here figured 

 (Figs. 203, 204) are in reality 

 the young of Melicertum, — 

 Melicertum being the only 

 Medusa allied to Staurophora 

 which has no eye-specks, — the close affinity between them is still 

 more strongly marked in the young of these two genera, which can 

 only be distinguished from one another by the presence or absence 

 of eye-specks. 



From an examination of the Medusa of Lafcea calcarata, I had 

 already come to the conclusion that the young Medusa was nearly 

 related to Staurophora and Melicertum. Having succeeded in finding 

 another Medusa evidently closely allied to it, I was not surprised in 

 recognizing a Melicertum of younger stage than any which I had 

 observed before. With the stage represented in Fig. 205, which has 

 been traced until there could be no doubt as to the genus to which 

 the young Medusa belonged, I was sufficiently familiar, from its fi-equent 

 occurrence in the latter part of the spring, to recognize at once in 



Fig. 202. Profile of Melicertuiu campanula, natural size. 



