52 bulletin: museum of comparative zoology. 



Obelia, sp. 



Eucope, sp. Agassiz, A., 1881, Bull. Mus. Comp. Zool. at Harvard Coll., Vol. IX. 

 p. 149. 

 A very few specimens of the medusa of an Obelia were found at the Tor- 

 tugas, Florida, late in June, 1898. The bell was disk-shaped and about 3 mm. 

 in diameter. There were 96 tentacles and 8 otocysts. The gonads were large 

 and spherical, and much distended with ova. The bell was colorless. Not 

 having seen the hydroid stock we are unable to determine whether or not 

 this Obelia is identical with any of the forms found at Newport, R. I. 



EPENTHBSIS, McCradt, 1857. 

 Epenthesis foUeata, McCkadt. 



Fig. 139, Plate 41. 



Epenthesis folleata, McCrady, J., 1857, Gymn. Charleston Harbor, p. 89. 

 Oceania folleata, Agassiz, A., 1865, North Amer. Acal., p. 70. 



Specific Characters. — Adult medusa. The bell is usually flatter than a 

 hemisphere, and is about 5 mm. in diameter. Its cavity is shallow, and the 

 bell walls diminish in thickness very gradually from the summit towards the 

 margin. There are 16 slender tentacles with well-developed basal bulbs. 16 

 otocysts alternate in position with the tentacles. Each otocyst contains a 

 single spherical otolith. The velum is well developed. There are 4 slender, 

 straight, radial canals and a narrow ring-canal. The proboscis is short and 

 simple and there are 4 slightly recurved lips. The 4 gonads are short and 

 linear and are developed upon the 4 radial canals near the circular canal. In 

 the young medusa they are found higher up upon the radial canals, but they 

 migrate centrifugally as development proceeds. The entoderm of the probos- 

 cis, tentacle bulbs, and gonads is of a decided green color. This medusa is 

 very common at the Tortugas, Florida, during the spring months, but becomes 

 rare after the first of June. We have found it abundant in the Bahamas 

 during the winter months. It is rare at Charleston, South Carolina, but 

 Brooks found both hydroid and medusa at Beaufort, North Carolina. 



EUCOPIUM, Haeckel, 1879. 

 Eucopium parvigastrum, no v. sp. 



Fig. 140, Plate 43. 



Specific CJiaracters.--The bell is half egg-shaped and is 1 mm. in height. 

 There is a very small apical projection. There are 4 very smaU radially 



