1 882.] The Siphonophores. 99 



the four radial tubes (n) from common junction at the apex of 

 the cavity to the bell rim. Their length is about equal, and their 

 course in the bell walls is direct, without division or bifurcation. 

 In the interval between the point of union of the covering-scale 

 and nectocalyx, suspended from the under side of the former, 

 hangs a flask-shaped body (p) which resembles very closely the 

 feeding polyps of Agalma. It contains the stomach, and at its free 

 end is found the mouth. The stomach cavity is in direct commu- 

 nication with the cavity of the covering-scale. From a point 

 near the origin of the polypite there is suspended a long flexible 

 highly contractile tentacle. This tentacle can be wholly re- 

 tracted at the base of the polypite, but when the Eudoxia is in 

 motion, is found reaching far behind the point of suspension, 

 gracefully extending to a great length. In addition to the poly- 

 pite we also find a cluster of bells (g) occupying the interval be- 

 low the covering-scale and its point of attachment to the necto- 

 calyx already mentioned. These bells enclose in their cavities, in 

 place of a proboscis, a globular mass of eggs. It will be seen 

 that the Eudoxia, which I have described, has female 1 sexual 

 bells only ; the male bells I have never been fortunate enough 

 to find. The sexual bells are found in all stages of growth, from 

 a simple bud to a well developed bell hanging from a stout 

 peduncle. The history of the growth of the egg after it is 

 dropped from the female bell, will be treated of in a special paper 

 on the embryology of Diphyes. 



The anatomy of Diphyes seems to me to sustain the homology 

 of the Siphonophores as pointed out in our account of the anat- 

 omy of Agalma. The absence of the float at the extremity of 

 the stem offers, no difficulty to this homology when we recollect 

 that the air bladder itself is only a modified medusa bell, and 

 consequently homologous to the anterior of the two bells of 

 Diphyes. The posterior nectocalyx is homologous to a true necto- 

 calyx, while the anterior represents the float of the Physophori- 

 dae. The axis of Diphyes, as that of Agalma, is homologous 

 with the proboscis of a Lizzia, and from its sides bud the medu- 



very impori 



and Ehlcs. m 



I diflcrcnco l-H-1 



