Bowerbankia. 
Z. ASCIDIOIDA. 
255 
214. Flem. Brit. Anim. 551 — Vesicularia pustulosa, Thump. Zool. 
111. 99, pi. 1, fig. 5—11. 
Hah . Parasitical on Fuci. Isle of Wight, Ellis. Cove Harbour, 
J. V. Thompson. 
This “ arises from the surface of marine fuci with a straight flex- 
uose 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 term distich ; each flexure of 
the stem and branches 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, on all of which in perfect speci- 
mens are placed oval transparent vesicles, furnished with animals hav- 
ing 8 tentacula : the rows of perforations having a spiral tendency, 
the clusters of vesicles hence present themselves in every direction.” 
Thompson . 
25. Bowerbankia,* Farre. 
Character. Polypidom confervoid , horny, creeping ; the 
cells sessile , unilateral , irregular , the inflected portion with a spi- 
nous or filamentous rim — Polypes ascidian. 
1. B. dens a, matted ; stem creeping ; cells from the sides arid 
upper surface, thickly set, elliptical: Polypes with 10 tentacula 
about one-third the length of the body, sparingly hispid along the 
outer side. Farre. 
Bowerbankia densa, Farre in Phil. Trans, an. 1837, 391, pi. 20 and 21. 
Hab. “ Found commonly on Flustra foliacea thickly aggregated in 
masses of half of an inch to one inch diameter.” Isle of Sheppey, 
Farre. 
“ The animal when fully expanded is about one-twelfth of an inch 
in length. In its retracted state it is completely inclosed in a de- 
licate horny cell, sufficiently transparent to admit of the whole struc- 
ture of the contained animal being seen through its parietes. The 
cells are connected together by a cylindrical creeping stem, upon 
which they are thickly set, and sessile, ascending from its sides and 
upper surface.” 
* “ Believing it to be new I have named it after my friend Mr Bowerbank, 
whose zeal displayed on this as on many other occasions where the study of na- 
tural history may be promoted, was mainly instrumental in inducing me to fol- 
low up these investigations, on account of the many supplies that I received from 
him, and I gladly therefore take the opportunity of acknowledging and record- 
ing the obligation that I am under to him.” Dr Farre. 
