PLATE X. 



FIG. 



1. SYNCORYNE GRAY ATA, p. 53, nat. size. 



1 a. The same, magnified. 1 b. A single polypite, more 

 highly magnified. 1 c. A polypite partially atro- 

 phied. 1 d. A polypite wholly atrophied, bearing- 

 two imperfect goiiozooids (T. H.). 1 e. A gono- 

 zooid almost fully developed. If. A female gono- 

 zooid, as it appears late in the breeding-season, laden 

 with ova. All the figures of S. gravata, with the 

 exception of 1 d, are after A gassiz, ' Contrib. to the 

 N. H. U. S.' vol. iii. pi. xvii. 



2. SYNCORYNE DECIPIENS, p. 56, polypites, magnified. 



From a drawing by Mr. Alder. 



