286 POLYZOA INFUNDIBULATA. 



loss to conceive. Upon tliis latter species in no case have I ever met 

 with spines ; and had they existed, traces of them would have been 

 visible on the sides of the cells, as they always are in G. aculeata, 

 even when the teeth themselves have been broken off." A. H. 

 Hassall. 



Of a slenderer habit than C. eburnea, which the species closely 

 resembles ; nor can I persuade myself that it is more than a variety, 

 — an opinion in which I am supported by Mr. W. W. Saunders. 

 He writes me, "The Crisia aculeata of Hassall is far from un- 

 common at Brighton and Hastings. I am very doubtful, however, 

 if the species be a good one, as C. eburnea has the cells sometimes 

 with a spinous process beneath them, as figured in the plate above 

 quoted of the Annales. The spinous character being then not 

 peculiar to C. aculeata, I do not see how it differs from the C. 

 eburnea. I believe M. Hassall's C. aculeata to be the perfect state 

 of C. eburnea." Jan. 5, 1841. 



4. 0. GENicuLATA, cells alternate, long and tuhular, with a 

 plain aperture. J. J. Lister. 



Tibiana, Lister in Phil. Trans, an. 1834, p. 385, pi. 12, fig. 5.— Crisia geniculata, 

 M. Edwards in Ann. des Sc. Nat. n. s. 9, 197, pi. 6, fig. 1. Mem. 5. 



Eab. Parasitical on littoral algse. Brighton, Lister ; where it was 

 also found on Rhodomela pinastroides by W. W. Saunders. Coast 

 of Ayrshire, plentiful, Rev. D. Landshorougli. I have Irish speci- 

 mens from W. Thompson, collected in Strangford Lough. 



Polypidom rooted by a creeping fibre, confervoid, about half an 

 inch in height, slender, dusky white, irregularly branched, the 

 branches erect, subgeniculate : cells biserial, alternate, each forming 

 a long cylindrical tube, of which the upper half is free and slightly 

 divergent, with a circular plain aperture. Between most of the 

 pairs of cells there is a flexible joint. The walls of the cells are 

 somewhat granulous, and the granules are connected by faint lines. 



This differs from C. eburnea in its more slender make and less 

 calcareous texture ; in the straightness of its secondary branches ; 

 and in the tubular form of the cells, which are distinctly alternate 

 and free at their apices. The granules on the parietes are also 

 smaller and more distant, and the striae almost obsolete. There is 

 sometimes one cell only between the joints, and sometimes there are 

 three cells, the new interspace originating from what may be called 

 the axis of the polypidom, and which forms the partition between the 



