﻿April, 1857.] 



ELLIOTT SOCIETY. 



165 



as seen in H. super ciliaris, but not generally, their usual course 

 being one of direct descent from their connection with the digest- 

 ive trunk to the marginal tube. In females heavy with ova, the 

 sexual lobes bulge downward at their lower extremities, so as 

 somewhat to overhang the mouth coming down between the ori- 

 gins of the oral tentacula. 



Disk of great transparency. Ovaries pale yellow. Digestive 

 cavity has each of its two extremities marked with a red spot. 

 Tentacular bulbs yellowish white, with a red spot within. 

 There is a variety in which the whole digestive cavity is of a 

 brickdust-red, and where this color is more conspicuous in the 

 tentacular bulbs. 



The larva of this species has about twelve contractile tentacula. 

 The polypidom grows about an inch or slightly more in height. 

 I have found it but once on a piece of wood which had evidently 

 been submerged for some time and probably considerably below 

 low water. I have not observed the actual liberation of the me- 

 dusa, but have obtained a number of young H. carolinensis by 

 keeping this hydra when in bud suspended according to Dalyell's 

 plan, in a jar of water. 



This species is one of the most common in our waters during 

 the summer. I first took it June 2d, and continued to find it in 

 greater or less abundance until November 4th, the last day on 

 which a specimen was found. It appeared to be most abundant 

 in June, somewhat less so in August, and again appearing more 

 frequently in September, after which its numbers gradually di- 

 minish along with that of the other summer medusae. I have 

 taken it in warm fair weather, at times when thunder storms were 

 rising, between heavy showers of rain, and after rain, in the 

 afternoon as well as the morning. There are scarcely any times 

 of day or any ordinary kinds of weather in which this medusa 

 may not be taken, yet sometimes under the most auspicious cir- 

 cumstances, fair sky, warm sun, smooth water, not a speci- 

 men is to be found, while perhaps other species are abundant. 

 This is more or less the case with every species. This genus is 

 not spoken of from the Mediterranean. The latitude of Charles- 

 ton harbor seems, therefore, to be its most tropical habitat, so far 

 as our present knowledge extends. We might suppose that its 

 presence here was due to our low mean annual temperature, but 

 it is found only during our tropical summer. 



