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PROCEEDINGS OF THE 



[April, 1857. 



Fig. 8 to 10. — Hippocre?ie Carolinensis. 

 Fig. 8. — Adult much enlarged. 



a, knobs representing contracted tentacula. 

 Fig. 9. — Young free medusa, with but from one to three tentacula, to each bulb. 

 Fig. 10. — Very young Cytseis-like free stage, with but four tentacula, and a, 

 three unbranched oral cirrhi. 



plate 11. 

 Fig. 1 to 3. — Eucheilota ventricular is. 



Fig. 1. — Full grown specimen, natural size; representing the carriage of the ten- 

 tacula, while the animal is sinking in the water. 



Fig. 2. — Specimen enlarged several diameters. The sexual organs are in an 

 abnormal condition, being represented by a plexus on one side, and by 

 two very slight fusiform swellings in those tubes which are on the right 

 and left side of the digestive cavity. 



Fig. 3. — A magnified view of an oval, sexual gland, with its large sinus of the 

 same form. 



Fig. 4. — Campanularia noliformis, from beneath ; showing the tentacular circle, 

 and the arrangement of the eight sense-capsules, a, with regard to the 

 radiate tubes. 



Fig. 5 to 7. — Obelia commissuralis. 



Fig. 5. — Young medusa viewed from above, and enlarged several diameters. 

 Fig. 6. — Ovary of an adult medusa. The usually circular outline is modified by 



the tension of the large ova, of some of which the germinative vesicles 



only are seen. 



Fig. 7. — Small arc of the tentacular circle, exhibiting three tentacula, with their 

 reentrant radices. With the middle one is connected a sense-capsule, a, 

 containing a single corpuscle. 



Fig. 8 to 9. — Eutima mira. 



Fig. 8. — Nearly of the natural size. 



Fig. 9. — Portion of the marginal cord — showing the form of one of the sense- 

 capsules, a, containing four corpuscles. 



plate 12. 



Fig. 1 to 2. — Eucheilota ventricularis. 



Fig. 1. — Portion of the tentacular circle, much magnified. 



a, great ganglion of the tentaculum. 



b, smaller ganglion of the greater tubercles bearing thread-cells. 



c, lesser ganglion for the small tubercles. The dark line connecting these 

 ganglia, a, b, and c, is the nervous cord, which accompanies the mar- 

 ginal canal, e, through its whole circuit. 



e, e, marginal and radiate tubes. 



d, tentacular bulb. 



/,/, the two small lateral tentacula, one of which is stretched out, and 



the other twisted together. 

 /' the enlarged and roughened termination of the smaller tentaculum. 

 Fig. 2. — Another portion of the tentacular circle, exhibiting d, a tentacular bulb, 

 without a lash, in course of development, a and / as in fig. 1 ; k. sense- 

 capsule of the same type as in Eutima, containing five corpuscles,* A, its 

 ganglion ; w, marginal cord. 



