254 BULLETIN OF THE 



Tentaculata and Nuda, accordingly as tentacles exist or are wanting. If this 

 feature alone be used in classification, Ocyroe would be placed in the group of 

 Nuda side by side with medusse like Beroe, with which it has few other ana- 

 tomical likenesses. If his classification be followed, Ocyroe must be regarded 

 as a connecting form between Ctenophora tentaculata and Ctcnophora nuda. 



Ocyroe renders necessary some modification in the phylogenetic tree which 

 Dr. Chun suggests, for the different genera of comb-bearing medusse. The 

 Beroids may have come from Bolina like jelly-fishes through Ocyroe rather 

 than directly from other tentaculated Ctenophores. A. Agassiz has pointed 

 out that this medusa has " structural characters of the Lobatce, Saccatce, and 

 Eurystonve." * It is the intermediate form connecting Beroe with Ctenophores 

 like Mnemiopsis or Bolina. Although most closely related to the Lobatce, it 

 resembles genera of the Eurystomatce in the absence of tentacles and the course 

 of the lateral tubes. The resemblance to the Saccatce is more distant. 



DISCOPHORA. 

 Cassiopea frondosa, Lamarck. 



Plate I. Figs. 7 - 19. Plate II. Figs. 1, 2. Plate III. Figs. 1 - 3, 9, 10. 



Cassiopea frondosa f is very common in the moat outside Fort Jefferson on 

 Garden Key (Tortugas Islands). Specimens were also found in the still 

 waters and protected shallows in the lee of the Mangrove Keys, near Key 

 "West City. 



Cassiopea frondosa is found lying on the coral mud at the sea bottom, with 

 its bell reversed and the oral region turned uppermost (PI. I. fig. 7.). When 

 transferred to the acpuarium it assumes a similar position, exhibiting httle 

 power of locomotion, but flapping the disk-shaped bell in a sluggish manner. 

 This motion seems to be confined almost wholly to the margin of the belL 

 While it cannot be said to be fixed to the bottom in such a way that movement 

 is impossible, it will be found, if its position from time to time be carefully 

 observed, that it does move from place to place, although the amount is very 

 small. It generally lies on its aboral region,^ sluggishly flapping the bell 

 margin in a monotonous manner, in general appearance, when -ten from the 

 boat floating abow it, resembling a small cluster of nullipores. The habit of 



* Bull. Mus. Comp. Zobl., IX. 3. 



t I regard this the same as P<>1 yclonia frondosa, Agass. Polyclonia according -to 

 L. Agassi/ 1ms twelve marginal sense bodies and twelve radial markings. The spei i- 

 nicns of C. frondosa studied by me had generally vixteen such structures. This is 

 true of young as well as of adult Cassiopnr, except in abnormal specimens. 



0. frondosa is closely related to Q. Andromeda, Each. 



} A similar posture has already been observed In Cassiopea by Ifertens ; in 

 r'niii'i, by I. ind in Medusa orquorca, Fursk, bj llcAndrew. (Ann. Nat. 



Hit., IV., 1869, p. 295.) 



