POLYZOA. 99 



on their upper surface, upon which in many we perceive 

 an equal number of oval transparent vesicles, or towards 

 the extreme parts of the branches, embryo vesicles. The 

 animals are very easily seen in all their details in this 

 species', from the great transparency of the vesicles, and 

 are provided with eight tcntacula. (f. 7, 8.) 



Vesicularia pustulosa (Sertularia of authors). This spe- 

 cies, very imperfectly known from the perishable nature of 

 its vesicles, first offered itself to notice without them and 

 as represented by Ellis N. Hist, of Corallines PI. XXVII. h, 

 B. but was subsequently discovered in its perfect state (PI. 

 T. F. 5.) It arises from the surface of marine fuci with a 

 straight flexuose stem, to the height of two or three inches, 

 giving off at each flexure a spreading branch, which in like 

 manner gives off secondary ones, all however, both primary 

 and secondary, lying in the same plane, they are hence what 

 Botanists teim distich ; each flexure of the stem and bran- 

 ches and each terminal branchlet is composed of a distinct 

 joint, each of which are perforated by a double row of holes 

 from 6 to 18 with elevated margins, fig. 7? 8, on all of 

 which in perfect specimens are placed oval transparent 

 vesicles, furnished with animals having 8 tcntacula, fig. 10 

 11 ; the rows of perforations having a spiral tendency, the 

 clusters of vesicles hence present themselves in every 

 direction (f. 6, — ) this species approximates in this last 

 character and in the unilateral regular disposition of its 

 vesicles to Serialaria, from which however all theVesicularise 

 differ in the vesicles being free and not as in that genus 

 agglutinated together in series or connected lines. Although 

 the animals of the Serialaria have not as yet been observed, 

 yet from the above coincidences and no oviferous vesicles 

 distinct from the others having been seen upon them, there 

 can hardly be a doubt but they are the habitations of Polyzoae 

 and not of Hydrae, and consequently would find place in our 

 Systems next to Vesicularia, and distinguished as a genus by 



