OYTAEIS. 189 



Cytaeidae L. Agassiz, 1862. 



Anthomedusae with interradial gonads; with solid tentacles ; with labial 

 nettle knobs or tentacles ; marginal tentacles simple, not in groups. 



As thus defined, the family includes not only the Thamnostomidae 

 Haeckel, Podocorynidae Hincks, and Cytaeidae L. Agassiz, already united 

 under the name Podocorynidae by Delage et Herouard (:01), but also the 

 Dendroclavidae. Delage et Herouard retain the latter group as a separate 

 family, on account of the presence in it of a peduncle of peculiar chordate 

 cells ; but the degree to which this structure varies in the various species 

 of the genus Lymnorea (p. 193), indicates that it is not a character of the 

 importance they supposed. In all other respects Cytaeidae and Den- 

 droclavidae are much more closely related to each other than is either to 

 any other family ; so closely, indeed, that their natural relationships are 

 probably better expressed by reducing them to the rank of subfamilies of 

 the one family, rather than retaining them as separate families. 



Cytaeinae. 



Cytaeidae Haeckel (79); Maas(:05). 

 Cytaeidae with simple marginal tentacles, not in groups ; labial nettle 

 swellings stalked (forming tentacle-like structures). No peduncle. 



Cytaeis Eschscholtz, 1829. 



Labial tentacles simple ; marginal tentacles permanently four, stout, solid. 



Maas (: 04 c ) has pointed out that the several Atlantic species of this 

 genus which have been described are certainly not all distinct, C. tetrastyla 

 Eschscholtz being probably an immature stage of C. nigritina Steenstrup, 

 while C. "pusilla is certainly a very young stage, and perhaps belongs to this 

 same species. C. macrogaster Haeckel seems to Maas well founded, because 

 of the size and shape of the stomach. From the Indo-Pacifie region two 

 species have been described : C. vulgaris Agassiz and Mayer ('99), and C. 

 herdmani Browne (: 05 b ). Since the present series shows intermediate stages 

 between the two, it appears that they in reality represent only a simple 

 6pecies, for which the older name C. vulgaris must be retained. In addition 

 to the species above mentioned Mayer (: 00 b ) has referred still another, C. 

 gracilis from the Tortugas, to this genus ; but inasmuch as this form already 

 has eight tentacles at the stage when the first medusa buds are formed, it 

 clearly does not belong to Cytaeis. 



