Explanation of the Plates. 101 



POLYZOA. 



Plate I. Fig. 1, /V^/cw/ar/a iHi6/ifa<rt, a principle stock of its natural size. 



Fig. 2. One of the terminal branches magnified, showing the animal in 

 different states of projection. 



Fig. 3. On» of the vesicles highly magnified with the animal in its retracted 

 state. 



Fig. 4. The same with the animal in its state of extension : «,tentacula. 

 i, gullet, c, stomach, rf, intestine, e, ovarium. Two pellets of excrementitious 

 matter are seen in the intestine. 



Fig. 5. Vesieularia pustulosa, in its perfect state when full grown, natu- 

 ral size. 



Fig. 6. A branchlet magnified, showing the sub-spiral distribution of its 

 groups of vesicles. 



Fig. 7. A branchlet highly magnified, partly denuded by the falling off of 

 the vesicles, showing the exserted animals, and the articuli into which it 

 appears to be divided. 



Fig. 8. One of the terminal shoots, without its vesicles, magnified. 



Fig. 9. A vesicle with the animal in its retracted state, magnified. 



Fig. 10. A vesicle with its animal exserted, magnified, a, tentacula. 

 h, gullet, c, stomach, rf, intestine, e, ovarium. 



Fig. 11. The tentacular head more highly magnified. 



Plate II. Fig. 1. a. Natural size of a principal stock of Vesiculaiia Cuseuta. 

 b, the same magnified. 



Fig. 2. A terminal shoot from which the vesicles have fallen off, showing 

 the irregular distribution of the perforations on which they were placed. 



Fig. 3. A vesicle highly magnified, with the animal in its retracted state. 



Fig. 4. A vesicle with the animal in its extended state, a, tentacula. 

 h, gullet, c, stomach, d, intestiue. e, ovary. 



Fig. 5. a, Pedicellaria exotica of its natural size. 5 b,the same magnified, 

 showing a number of individuals originating from one of the radical tubes. 



Fig. G, A vesicle highly magnified with the animal retracted and bent up 

 as usual into an S like form. 



Fig. 7. A vesicle highly magnified with the animal extended, its details 

 obscured by the greater opacity of its parieties. 



Fig. 8. One of tentacula more highly magnified showing the respiratory 

 lamina in profile. 

 LATE 111. Fig. 1. A principal branch of Fesicularia spinosn of the natural size. 



Fig. 2. A dead branch stript of its vesicles, as usually seen amongst the 

 rejectamenta of the Sea. 



Fig. 3. The basis of an old stock formed by an accumulation of tubes, 

 giving rise to brauches similarly constructed, magnified. 



Fig. 4. Three joints of amain branch magnified, showing the manner in 

 which the vesicles were distributed upou it, and the ramuli given off in pairs. 



