Plate VII. 



Fill. I. Oral disk oi Edwardsia AUmanni , 'Sl^L, completely contracted. 

 Enlarg'ed. 



Fig. '2. The same, with the tentacles partially expanded. 



Fi;;. :^. Anterior portion of the sheath and pouting rim of the mouth. 

 Viewed laterally. 



Fiff. 4. A single tentacle. Enlarged. 



Fif/. 5. View of the posterior part of Fdwanhia Goodsiri, M'l., showing 

 the " blown-bladder " aspect. 



Fi;/. (i. The oral disk with expanded tentacles. 



Fi;/. 7. A single tentacle. Enlarged. 



Fii). S. An entu-e colony of Akyonmm diyitatum, L., with the polyps in 

 varying degi'ees of expansion. 



Fig. 9. External -view of a polyp on a level with its cell. 



Fig. 10. The same, more expanded. 



Fig. 11. A polyp half-expauded. 



Fill. 12. A polyp of the same, much attenuated, showing the minute 

 spicula and the somewhat fusiform aspect of the expanded 

 arms. 



Fig. 13. Boris repanda, A. & II., in process of spawning : u, the dimple 

 of the foot. The arrow marks the direction of its turning. 

 Seen through a glass vessel. 



Fig. 14. The same, in another position, with the cloak much folded. 



Fig. 15. Spawn of the foregoing. The single interrupted chain of ova 

 appended thereto is exceptional. 



Fig. 10. A scolex of Tctrarhiinchux from the stomach of Cancer pagurus, 

 encysted. Probably from the debris of lishes eaten by the 

 crab. X about 60 diameters. 



Fiq. 17. The same, separated from the sheath and somewhat compressed. 

 X 65 diam. 



Fig. 18. Echinorhynchus strv.mo.'im, Rud., from the intestine of a common 

 seal {Pliocn vitulimi) caught at St. .\ndrew3. x 60 diam. 



