[41] 



MEDUSA FROM THE GULF STREAM. 

 KhIZOPHYSA UVARIA, S]). nov. 



967 



A single specimen of a new and characteristic L'hizophysa was taken 

 on tbe surfiice at Station 2038. 



The float pear shaped, pointed at apex, witli zone of dark pigment. 

 Length, 5"^™; diameter, 3™"^. Apical opening present. Air sac with 

 bodies in cavity hanging from nuder side within tbe tloat as in li. fili- 

 formis. Stem short, probably broken, the proximal portion alone re- 

 maining. 



At the junction of the stem and float we find, as in rterophysa, a cluster 

 of half-developed polypites, at the base of which is a botryoidal cluster 

 of gonophores (?). Belovv' the first cluster of i)olypites there is a smooth 

 portion of the stem, and then another cluster of polypites arising from 

 a somewhat thickeued base. In the second cluster of polypites the 

 basal organs near the point from which these organs arise resembles 

 closely the gonophores figured by Studer* in E. inermis. Below the 

 second cluster of polypites we have a portion of the stem still remaining, 

 but with the distal end broken ofl", showing the same smooth character 

 as the section of the axis between the first and second cluster. In B. 

 inermis, Studer, we have the same condition, although in this species a 

 single polypite arises from the vicinity of the gonoi)hores, while the 

 continuation of the stem bears polypites without gonophores. There is, 

 moreover, in R. inermis nothing corresponding to the proximal cluster 

 of undeveloped polypites and gonophores as I have described them in 

 B. uvaria. 



The individual polypites of R. uvaria resemble those of inermis in the 

 structure of the distal extremity, in which is placed the mouth opening 

 where a small button-shaped end is slightly constricted from the polyp- 

 ite. There are no tentacles in the single specimen studied. No ptera 

 or wing like appendages on polypites. 



The characteristic structure of this Rhizophysa, by which it is dis- 

 tinguished from all others, is the grouping of the polypites and gono- 

 phores into bundles at intervals along the axis and the want of tenta- 

 cles. We have here something similar to the arrangement of these 

 structures in tlie well-known Apolemia uvaria, except that in R. uvaria 

 nectocalices, bracts, and similar structures are not developed. The 

 sexual bodies are here grouped at the bases of the polypites, as in the 

 species R. graeiUs, Few., from the Florida Key«. 



There are several features in R. uvaria recalling jK. inermis and marked 



* Zeit.f. wiss. Zool., Bd. xxxi, Taf. I, Fig. 3, 



