BAHAMA MEDUSA. 25 



knobs (see Fig. 55, Plate VI). When the medusa is 8 mm. in diameter (Fig. 

 52, Plate V), there are sixteen of the tentacles that project from the sides 

 of the bell, and about an equal number of the flexible, coiled tentacles that 

 arise from the bell margin. There are thirty-two otocysts, a pair flanking each 

 of the sixteen tentacles that arise from the sides of the bell, and twelve cen- 

 tripetal diverticulae from the circular vessel that extend into the gelatinous 

 substance of the bell. The gonads have not yet made their appearance. The 

 tentacles that arise from the sides of the bell have begun to develop their 

 peculiar pad-like disks upon their aboral sides (see Fig. 56, Plate VI). These 

 pad-like disks, which are evidently homologous with the adhesive disks in 

 Gonionemus and Cubaia, are developed from the aboral side of the primitive 

 nematocyst knob of the tentacle, as is shown in successive stages represented 

 in Figs. 55, 56, 57, Plate VI. We see, then, that the youngest medusa of Olin- 

 dias may be said to be in the "Gonionemus stage," for it has only tentacles of 

 the "sucker-bearing" set, and the circular canal is simple without diverticulaj. 

 It seems probable therefore that Olindias is descended from a Gonionemus- 

 like medusa. 



Olindias tenuis is one of the few medusiB that thrive best on the shallow 

 flats of the Bahamas and Florida coast, and is very abundant during the sum- 

 mer months in Nassau Harbor, and at Key West, Florida. 



Liriope scutigera, McCeady. 



Fig. 31, Plate IV. 



Bkooks, W. K., 1886 ; Mem. Bost. Soc. Nat. Hist., Vol. Ill, p. 373, PL 41, 43. 

 MoCbadt, J., 1857 ; Gymn. Charleston Harbor, p. 106. 

 Xanthea scutigera, Habokel, E., 1864 ; Qeryoniden, p. 34. 

 Iiiriantha scutigera, Haeokel, E., 1879 ; Syst. der Medusen, p. 287. 



Adult Medusa: Bell bluntly conical, flatter than a hemisphere, and about 

 8 mm. in diameter. Four long, hollow, radially situated tentacles. In young 

 specimens there are four short, stiff, solid, radial tentacles that project from 

 the sides of the bell, but these are cast off or absorbed before the medusa is 

 mature, and are replaced by the hollow, permanent tentacles. There are 

 eight otocysts, each having a single spherical otolith. The otocysts project 

 inward into the bell cavity above the velum and are radial and interradial in 

 position. The velum is well developed. There are four slender radial canals and 

 a simple narrow circular vessel without centripetal diverticulse. The manu- 

 brium is at the extremity of a long tapering peduncle which projects beyond 

 the velar opening. The four cruciform lips are curtain-like and folded and 



