Notes on some Hydromedusae from the Bay of Naples. 561 



As will be seen from the foregoing account, we bave here a 

 medusa which is eitlier extremely degenerate, or one of very prim- 

 itive type. Its development within a chitinous capsule (gonangium ?), 

 associated witli the sporosac-like hìstory of the gonophore would 

 seem to suggest the latter alternative. So far as I am avvare the 

 development of Anthomedusae within gouangia is quite rare if not 

 whoUy anomalous. The unique gonophores of Dicoi'yne are prob- 

 ably of very different character and significance. 



In 18S } Lendenfeld (op. cit.j described a new hydroid and 

 medusa, EucopeUa ca?npanularìa , which appareutly sustains a re- 

 lation to the Campanularidae similar to that of the medusa herein 

 described to the Tubularidae. The medusae of these forms bave 

 much in common, such as shape, size, rudimentary organs, etc. 



Moreover, in the origin of the eggs, their migration into the 

 gonangium Avhich later gives rise to the medusae, the nutrition of 

 the eggs and the general character of their later history, the corre- 

 spondences between the two are very interestiug. Lendenfeld's 

 description of Eiicopella also confirms the Suggestion of a preceding 

 Paragraph that these are probably both generalized, or primitive 

 types of medusae, in which the origin of the eggs, apart from, and 

 prior to the Organization, of the medusa, points to a condition si- 

 milar to that found in such hydroids as Hydractmìa, Clava, etc. in 

 which there is nothing more than a sporosac within which the eggs 

 develop after their origin in the body of the animai and later mi- 

 gration into these specialized nutritive capsules. 



As the eggs approach maturity two rather marked cbanges are 

 more or less apparent, one involving the character of the cytoplasm, 

 the other that of the nucleus. In their earlier history the egg cyto- 

 plasm consists of a more or less viscid matrix through which is 

 distributed a fìnely granular matter, the whole forming a somewhat 

 homogeneous body. With the assumption of the spherical shape 

 and typical size (about 0.9 mm), the cytoplasm becomes more pre- 

 dominantly granular in character and at the same time there appears 

 in many cases a tendency toward vacuolation. I bave elsewhere^ 

 called attention to a similar condition in the eggs of Pennaria at 

 about tbis period in their history and the same tbing bas been 

 uoted bv Metschxikoff 2 and others. In Pennaria it bad seemed 



1 Arch. Entwickhmgsmech. 18. Bd. 1904 pag. 462. 

 - Embryologische Studien an Medusen. Wien 1886. 



