DESCRIPTION OF PLATE IV. 
On a Cyst upon the Olfactory Nerve of a Horse, hy J. B. Simonds, Esq, 
Fig. 
1. The cyst containing a crystal of oxalate of lime. — a, Bell-shaped spot 
in interior of cyst. — A moveable mass of granular matter. 
On the Development of Tubularia indivisa, hy J. R. Mummery, Esq. 
16, 17. Fully developed head of Tubularia indivisa, loaded with repro- 
ductive capsules. 
13. Newly-formed head. 
14. The same, showing arrangement of ovaries. 
12. Internal surface of head (the oral tentacles removed), exhibiting 
twelve lines radiating from base of cavity, and corresponding with 
external ovaries. 
15. Base of two marginal tentacles. 
18. A group of reproductive capsules from the full-grown head, in several 
co-existing stages of development. 
2, 3, 4, 5, 6. Progress in the extrication of young Tubularia, at intervals 
of one hour. 
8. A young animal of the ellipsoidal form. ~ 
7a. Ditto, of the discoidal variety. 
7b. The same, thirty-six hours after emerging from the capsule. 
7c. The empty capsule. 
10. The specimen, fig. 8 — three days after — still free. 
9. Ditto, on the fifth day, having affixed itself at base. 
11. The young animal at the expiration of six weeks ; the head having 
now acquired a pale rose tint, and the peripheral tentacles increased 
to sixteen. 
