ALCYONELLA. 123 



Plate XXX. Fig. 2. Summit of one of the protuberances of fig. 1, shewing the 

 form of the hydrse. 



3. Ova floating. 



4. Ova remaining in situ after decomposition of the Alcyonella, 



fig. I. 



5. Alcyonella (ancejjs), specimen investing a larch twig. 



6. Fleshy prominence of fig. 5 with hydrse. 



7. Fleshy prominence of another specimen with hydrse. 



8. Hydra. 



9. Cellular formation of part of the surface of fig. 5. 



10. Cellular formation of another specimen diffusing a very thin 



stratum. 



11. Under surface of a specimen where applied to the substance 



invested. 



12. Entire hydrse, together with the conical prominences a, b, c, 



of decayed hydrse, containing ova. 

 18. Ova in situ depressed in a portion of fir bark, the Alcyonella 

 having decayed. 



14. Other ova also in situ. 



15. Ova on the same bark. 



16. Young hydra from an ovum of fig. 15. 



17. Nascent hydrse developed from ova on the same bark, in- 



terspersed with ova still entire. 



18. Vesicles of uncertain nature dispersed on the bark. 



All the figures of this Plate, except figs. 1, 4, 5, 13, 14, 

 are enlarged. 



§ 3. Plumatella.— Plates XXXI., XXXII., XXXIII.— None of 

 the Lunate tribe of Zoophytes exceed the luxuriance or the beauty of the 

 Plumatella, nor do any of them so narrowly resemble a plant. The deli- 

 cacy of its parts, their extraordinary number, the richness and vivacity of 

 the efflorescence, are all the best adapted to excite our interest, and at- 

 tract our admiration. 



Nevertheless, the diversity of aspect which is almost universally inci- 

 dent to zoophytes, does not diminish the wonted perplexities assailing the 

 naturalist in his attempts to assign to each its proper place, should it ap- 

 pear that there are more than a single species. But in truth, the most 



