BRYOZOA OF WOODS HOLE REGION. 253 



Genus ANGUINELLA Van Beneden, 1844. 



AnguinelJa palmata Van Beneden [PI. xxvm, fig. 78, 783.] 



Van Beneden 1844, p. 58. 



Zoarium with erect branches bearing the zooecia, which are not at all constricted at the base. The 

 zooecia are cylindrical and bluntly rounded at the apex, irregularly situated on the branch, opaque 

 with impregnated earthy matter, tentacles about 10 in number. Height, according to Hincks (1880), 

 from 3 to 8 inches, but I have seen no specimens on the American coast more than an inch in height, 

 even where it grows abundantly, as at Beaufort, N. C. 



The species may be very readily overlooked on account of its peculiar growth habit, which resem- 

 bles that of a small brown alga, and from the fact that it is rendered obscure by a layer of mud embedded 

 in the ectocyst. I have taken it but once in the Woods Hole region, at Fish Hawk station 7659, in Buz- 

 zards Bay, where a few small colonies were dredged. 



Family VESICULARIID Hincks, 1880, 



Stolonate, the zooecia arising singly or in clusters from the stolon, or from erect branches; zooecia 

 well marked off from the stalk or stolon, often deciduous. 



KEY TO GENERA. 



1 . Zooecia clustered in double rows arranged spirally on the stems which are erect and branching . A mathia. 

 Zooecia not so arranged 2. 



2. Zoarium with a creeping stock, from which may arise erect shoots; zooecia irregularly disposed or 



occasionally clustered Bouerbankia. 



Zoarium erect, phytoid, rooted by fibers. Zooecia arranged in a single series on one side of the 

 stem Vesicularia. 



Genus BOWERBANKIA Farre, 1837. 



Our species of this genus are creeping, with occasional branches reaching out in a wandering fashion 

 as though in search of a support. The zooecia are irregularly disposed in our species, though in B. 

 imbricata, which has been reported doubtfully from Canadian waters, they are arranged in groups. 



KEY TO SPECIES. 



A pointed or divided process near the base of the zooecium on its outer side var. caudata. 



No projection on the basal portion of the zooecium gracilis. 



Bowerbankia gracilis Leidy. [PL xxvm, fig. 80, 8oa, Sob, 8oc.] 



Leidy 1855, p. 142. 



Verrill and Smith 1874, p. 709 (Vesicularia gracilis). 



Verrill 18790, p. 28 (Vesicularia gracilis). 



''Polydome delicate, creeping, branching, white. Cells cylindrical, erect, about l /^ of a line in 

 length, without appendages at their orifice, the margin of which is retractile with the inhabitant of 

 the cell. Polype provided with 8 ciliated arms. Intestine with a strong gizzard. Pt. Judith." (Leidy.) 



In its most distinct form the gracilis of Leidy is smaller than caudata, the stolon entirely creeping, 

 the zooecia slender and colorless, and attached to the upper surface of the stolon either singly or in 

 clusters, and in such zooecia there is usually no indication of any caudate process. The careful study 

 of any such colony, however, in all large colonies that have come under my observation, has revealed 

 occasional zooecia attached to the side of the stolon, either singly or in pairs after the manner of caudata, 

 and in these laterally attached zooecia a caudate process, sometimes as well developed as in caudata, 

 is often present. All sorts of intergradations in the size of the process are present, and in size and color 

 also the two forms intergrade. For these reasons, therefore, I unhesitatingly place caudata as a variety 

 of gracilis. There is, furthermore, no difference in the distribution of these forms in our region, and 



