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PROCEEDINGS OF THE 



[April, 18.57. 



First. In its continental type it is identical with those of Grand 

 Manan, Boston, and Long Island Sound. 



Second. Its natural climatic analogies are with the Fauna of the 

 Mediterranean. 



Third. It has strong analogy, if not partial identity, with the 

 Fauna of the southern coast of Great Britain, which must be at- 

 tributed to the Gulf Stream. 



EXPLANATION OF PLATES, 8, 9, 10, 11, 12. 



PLATE 8. 



Fig. 1. — Turritopsis nutricula — (young.) 



/, the four incipient labial tentacula, three of which are seen in this profile 

 view. 



t, the mass of large transparent cells, above the digestive cavity. 



Note. — Ocelli are present at this stage, but have not been distinctly given in 

 the engraving. 



Fig. 2, 3. — Saphenia apicata. 



Fig. 3 — contracted digestive trunk — a, cavity formed by the contraction of the 



elongate transparent portion of the digestive trunk. 



o, ovaries surrounding the true digestive cavity. 

 Fig. 4 to 5. — Zanclea gemmosa. — (young.) 

 Fig. 4. — p, clavate appendages of the tentacula. 



x, one of the characteristic groups of thread-cells, seen in profile. 

 Fig. 5. — Magnified view of one of the clavate appendages, fig. 4. 



corpuscles contained in the enlarged extremity. 

 Fig. 6 to 8. — Sarsia turricula. — (young.) 

 Fig. 6. — Oldest stage observed. 



Fig. 8. — Younger stage, in a^ somewhat contracted condition. The slight promi- 

 nences, which enrich the surface, are not represented in fig. 6. 



iig. 7. — Tentaculum of fig. 7 enlarged, showing the arrangement of the tufts of 

 thread-cells. 



Fig. 9 to 10. — Eudoxia alata. 



Fig. 9. — Basal medusa. 



a, air chamber. 



Fig. 10. — Sexual medusa. 



c, the elevated crests from which the specific name has been derived, 

 o, ovary and ova. 



plate 9. 



Fig. 1 to 2. — Dipurena strangulata. 



Fig. 1. — I, lower cavity of the digestive trunk. 



u, upper cavity of the same. 

 Fig. 2. — Tentaculum magnified. 



c, cavity of the terminal bulb. 



