MAYER: MEDUS/E FROM THE TORTUGAS, FLORIDA. 33 



The basal bulbs of the long tentacles are large and hollow. "When fully 

 stretched, the long tentacles attain a length of 4-10 times the bell height. The 

 velum is well developed. There are 4 broad radial tubes, and also a broad 

 circular vessel with jagged outlines. The proboscis is Hask-shaped, the lips 

 being flanged and quite prominent. The mature sexual products are found in 

 the ectoderm of the proximal portion of the proboscis where the outer surface 

 is folded into a complex series of ridges. The bell is transparent. The ento- 

 derm of the tentacle bulbs and of the proboscis is brick-red. In some indivi- 

 duals the entoderm of the 4 radial tubes and of the circular vessel exhibits a 

 faint tinge of red. The specimens of this species from the Tortugas, Florida, 

 are peculiar in that the red color of the proboscis and tentacle bulbs is streaked 

 with black. In some cases, after the medusie had been confined in aquaria for 

 a number of days, the proboscis and tentacle bulbs became wholly black. 



This medusa is very conmaon at Newport, Rhode Island, but does not extend 

 north of Cape Cod. It is found all along the southern coast of the United 

 States, but is rare at the Tortugas, Florida. 



Hijdroid, and young medusa. — Brooks, 1883, describes the hydroid of this 

 species. It is a Perigonimus, very much like P. minutus, Allman (1871 ; 

 Tul)ularian Hydroids, p. 324, Plate XI. Figures 4-6). It was found growing 

 upon the lower surface of the shell of Limulus, fastened to the sand tubes of 

 Sabellaria. The stems are simple and unbranched and are about 0.2 mm. in 

 height. The stems are covered for about two thirds of their length by a deli- 

 cate, closely adherent film of perisarc to which foreign particles become 

 attached. The stomach occupies about one fourth or one fifth of the stem, 

 from which it is separated by a slight constriction. Each polypite possesses 

 ten tentacles, which point alternately backwards and forwards, those pointing 

 forwards being a little longer than the others. The medusae are attached by 

 very short peduncles to the sides of the stems. When the medusa is set free it 

 is about 0.5 mm. in height, and there is no trace of the apical projection, which 

 develops in the course of about 8 days. 



In an abnormal individual of this species found at Newport, Rhode Island, 

 in July, 1892, there were 4 long tentacles, one at the base of each radial canal. 

 This medusa was maintained alive in an aquarium for more than a month. 

 When first found it had but two diametrically opposed tentacles, each at the 

 foot of a radial canal. The other pair of large tentacles developed later, after 

 the first pair had attained their full length. The medusa then possessed 4 long 

 tentacles and 12 small rudimentary tentacle bulbs. This variation is interest- 

 ing, as it illustrates the close relationship between Stomotoca and Modeeria. 



