110 



MEDUS.E OF THE WOULD. 



ring-canal. The gonads are 8 adradial, transversely folded, ectodermal regions on the sides of 

 the stomach. Stomach yellowish-brown or green, tentacle-bulbs crimson or purplish. 

 Found off the coasts of Great Britain. Hydroid unknown. 



I have seen medusae oft" the coast of Cornwall, Eng- 

 land, which were identical with Stoniotoca apicata of 

 America. 



AMERICAN MEDUSA. 



In the adult American medusa the bell is about 4 

 mm. high and 2 mm. wide. There is a large apical 

 projection which is hollow in the female, but usually solid 

 in the male medusae. The bell-walls are thin and the 

 sides vertical below, but slopinginward above to a pointed 

 apex. There are 2 long, diametrically opposed ten- 

 tacles, with large, tapering, hollow basal bulbs. There 

 are no ocelli. These long tentacles are highly contractile, 

 but are usually about as long as the bell-height. Their 

 shafts are covered with small wart-like clusters of nema- 

 tocysts. In addition to the 2 long tentacles, there are 6 

 or more small rudimentary tentacle-bulbs upon the bell- 



FIG. 60. Stoniotoca dinema, male. From life, by 

 the author. Mousehole, Cornwall, 

 England, October 28, 1907. 



Synopsis of the Species of Stoniotoca. 



