$52. 



THE POLYPI. 



57 



This metamorphosis is completed when the skin is 

 covered by a brown and solid layer, and new indi- 

 viduals are developed by gemmation from the two 

 Polyps (See Meyen, Isis, loc. cit.). I have seen 

 the development of the coralla of Cristate/la mi- 

 rabilis and Plumatella campanulata occur in 

 the same way. With the Cristatellae, gemmae of 

 new Polyps are often seen to arise from the skin, 

 even after the escape of the two Polyps, and before 

 the young colony has become at all fixed. At this 

 epoch of development these Polyps have been taken 

 by Cuvier for a distinct species, and called Crista- 

 tella mucedo. See Roesel, loc. cit. p. 559, Taf. 



XCI. ; and Turpin, Ann. d. Sc. Nat. VII. 1837, p. 

 65, pi. II. and III. 



Infusoria-like embryos have been observed also 

 by Steenstrup (Untersuch. loc. cit. p. 66, Taf. I. fig. 

 21) with Coryne sqiiamaia, and by Sars (Faun, 

 hctoral. Norveg. p. 7, Tab. II. fig. 7-11) with Po- 

 docoryna carnea. The round eggs moving about 

 by means of cilia, which Reid (Ann. of Nat. Hist. 

 XVI. p. 392, 397, pi. XII. fig. 9, 13) has observed 

 in the visceral cavity of Pedicellina echinata, 

 and in special capsules with Flustra avicularis, 

 were probably embryos also.* 



* [§ 52, note 3.] The embryonic development 

 of the Bryozoa has been carefully wrought out by 

 yan Beneden. See Recherch. sur les Bryozoaires, 



&c., Mem. Acad. Bruxelles. XIX. See also All- 

 man, Report, loc. cit. 1850, p. 322 — Ed. 



