[43] MEDUSA FROM THE GULF STREAM. 969 



from one end to the other of this structure. These bands are regarded of 

 generic worth. The depth at which this genus, as well as other supposed 

 deep-sea Rhizophysidfe taken from *' dredge ropes," has been recorded, 

 does not necessarily conform to that assigned to the station. The fact that 

 they are found clinging to the rope may mean that they come from any 

 depth less than the sounding. The great relative size of the float of most 

 known species of Rhizophysidse, as compared with that of other Phy- 

 sophorae, would seem to imply that Bhizophysa,like its relative Physalia, 

 is a surface genus, lu li. JEysenhardtii, Geg., a species which I have 

 taken at the Bermudas on the surface of the water, the relative size of 

 the float is very great; The same is true of the supposed deep-sea 

 species described by Studer. 



The habit of clinging to a foreign body, as a rope of the dredge when 

 it is drawn through the water, is exemplified in B. Uyftenhardtii, where 

 the tentacles must almost be torn from their hold before they loose them- 

 selves from their connection with a foreign body. In the last-mentioned 

 species this power is lodged in the tentacles and their branches, but in 

 the new genus Pterophysa it is i^ossible that additional structures on 

 the polypites, specially adapted for that function, have been added to 

 increase this prehensile power. These structures are the lateral wings 

 (ptera)* 

 which characterize the polypites of this genus. 



The stem and the various ajjpendages of Pterophysa are found to be 

 so closely twisted together that it is hopeless to endeavor to uncoil it. 

 Consequently the general outlines of the body are difficult to make out. 

 Many of the polypites, although broken from their attachments, are in 

 good condition. 



Pterophysa grandis, sp. nov. 



(Plate X, Figs. 1, 2, and 3.) 



The float is oval, oblong, lO""™ in longer, 5™™ in shorter, diameter. At 

 its apex is an indication of the pigmental zone, and a well marked open- 

 ing, closed by a sphincter muscle, is seen in one specimen. The form 

 of the float and its relation to the axis indicates that, like the species 

 B. Eysenhardtii, Pterophysa, carries the longer axis of the float vertical 



* In a cross-section of a Bhisopliysa {B. covifera) polypites figured by Th. Studer oj). 

 cit. PI. II, Fig. 17, two structures are figured, which are probably the same as the 

 wings of Pterophysa. They are not represented in PI. I, Fig. 4, where the polypite of 

 M. conifera is figured. I do not at present understand how a cross-section of the poly- 

 pite of conifera (PI. I, Fig. 4) can give the strange structure shown in PI. II, Fig. 18. 

 In the latter figure, which is a " Querschnitt durch den Basaltheil einesPolypen von 

 B. conifera," we have structures which resemble ptera, but are much wider than in 

 Pterophysa, and bear fringed structures on their edges. Although these structures 

 are four or five times the diameter of the " polyp ", in PL I, Fig. 4 (" Polyp von Phizo- 

 phj/sa conifera mit contrahirtem Magentheil") they are unreprescuted. P. conifera 

 probably belongs in my genus, Pterophysa, on account of the possession of these bands. 



