PLATE 18. 



Stephanomia amphitridis. 



Fig. 1. General view of the siphosome. From a photograph. Natural size. 



Fig. 2. A portion of the siphosome. The bracts have been removed, but the muscular lamellae 

 (Br.) on which they were borne show their position.? on the stem. The right hand end is distal. X 4. 



Fig. 3. An adult tcntillum. X 20. 



Fig. 4. A male gonophore. X 15. 



Fig. 5-S. Various views of bracts. Figs. 5, 8, are from the dorsal surface of the siphosome, 

 fig. 6 from the ventral, fig. 7 from the lateral. X 2. 



Agalma elegans. 



Fig. 9. A segment of the siphosome, with the mature bracts removed, but with their muscular 

 lamellae (Br^.) still in place. There is one very young bract (Br'.). X 20. 

 Fig. 10. Tentillum, nearly mature. X 35. 



Fig. 11. A younger tentillum, in which the involucre encloses only one coil of the cnidoband. X 35. 

 Fig. 12. A mature bract, showing ridges, and trideutate margin. X 10. 

 Fig. 13. Lateral view of same. 



