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PROCEEDINGS OF THE 



[April, 1857. 



an opportunity of connecting with this species the name of my 

 friend, Prof. Lewis R. Gibbes, who pointed out to me the first speci- 

 mens I examined, lying on the beach of Sullivan's Island. 



The young buds on the hydra are at first mere buttons. (PI. 10, 

 fig. 7.) They grow and become heart-shaped in outline, as the four 

 large, marginal bulbs are formed, with their very distinct sinuses. 

 The external transparent tissue of each bulb becomes first bifid, as 

 far as I can ascertain, then quadrifid or trifid, (fF. 6 and 5.) At this 

 time the digestive trunk almost entirely fills the cavity of the yet 

 closed bell. The bud elongates ; the tentacular bulbs make the bell 

 broader at its lower than at its upper (attached) end. The little 

 points of each quadrifid bulb next elongate ; slight contractions are 

 visible in the bell, which probably at this time becomes open. The 

 next observation, a few hours later, finds the Medusa free, and hav- 

 ing three or four straight, stiff tentacula, with rings of thread-cells, 

 (fig. 4.) At this stage the digestive trunk is still nearly of the 

 height of the bell; when contracted, however, it forms only a hemi- 

 spherical mass in the upper portion of the bell-cavity. No oral 

 cirrhi ; no distinguishable sexual organs. At this stage the N. 

 Gibbesii may be distinguished from Hippocrene Carolinensis, by the 

 large size of its marginal bulbs and digestive trunk, and the fact 

 that it has three or four tentacula to each bulb. 



In the next stage which has come under my observation, the 

 base of the digestive trunk is vei^r broad ; its height less in pro- 

 portion to that of the bell. There are four long-shafted, oral 

 cirrhi, bifid at their extremity ; the number of tentacula has in- 

 creased. Shortly after, ocelli have appeared. The young medusa 

 is still distinguishable from the young of Hippocrene Carolinensis 

 by the long shafts of its oral cirrhi. 



Some intermediate stages I have not been able to observe. The 

 next form is that wherein the sexual glands are like those in Hip- 

 pocrene, but have a broad base upon the four radiate tubes, being 

 not constricted above, as in the genus just mentioned. See fig. 3, 

 pi. 10. At the same time the clavate tentacula are quite conspic- 

 uous, and on each side of that pair there are four or five filiform 

 tentacula to each bulb ; 4+1 + 1 + 4. Next, the sexual organs are 

 discovered, already half-way down the radiate tubes. See fig. 2. 

 The animal increases in size, the tentacula in number, the oral 

 cirrhi become very much branched, and their delicate dendritic 

 form gives them an extreme beauty. Lastly, the sexual glands 

 reach fully two-thirds of the distance from the base of the stom- 



