COELENTERATA 55 



Syncoryne mirabilis Agassiz 



PLATE III. Fig. 4 



Almost hemispherical, 6 to 12 mm. in diameter; 

 1 long- tentacles. 



Arctic seas to New Jersey; not common in New 

 Jersey. 



Obelia 



PLATE III. Fig. 10 



The medusae of this genus are flat and discoid 

 and very minute — 1 mm. at time of liberation from 

 gonosome and up to 5 or 6 mm. at maturity. It is 

 almost impossible to distinguish the various species 

 of this genus. 



Blackfortia virginica Mayer 



PLATE III. Fig. 6 



Bell about 14 mm. wide, somewhat higher than 

 a hemisphere with relatively straight, sloping sides 

 and rounded apex. About 80 long, slender tentacles 

 with short swollen basal bulbs. Usually one litho- 

 cyst (minute sense organ) between each pair of 

 tentacles. Black pigment is conspicuous near the 

 tentacles. No hydroid stage is known. 



Originally described by Mayer from Hampton 

 Roads, Virginia (October, November, 1901) ; more re- 

 cently (August, 1931) found in Mullica River, New 

 Jersey. 



