PLUMATELLA ELEGANS. 107 



up the tentacles. Egg (statoblast) black, long, oval ; sides nearly parallel ; margins pellucid, 

 yellow, sharp, broad, and reticulated. 



" This species was procured rather abundantly in Bromley Lough, and does not appear 

 to vary much. At first sight, large patches of it have the appearance of being formed of a 

 single polypidom ; but on close examination are found to be composed of many, and rarely 

 to number more than six or eight, cells in each. The commencement of each polypidom 

 has the black envelope of the originating egg (statoblast) adherent." 



Plumatella Allmani certainly comes very close to P. emarffuiata and P. diffusa; it is, 

 however, distinguished from both by its cells being claviform, while they are cylindrical in 

 P. emarc/inata, and keg-shaped towards the orifice in P. diffusa. Mr. Hancock describes the 

 ccenoecium as keeled, but makes no allusion to the oblique or notch-like termination of the 

 earthy deposit in the ectocyst, which is so distinct a character in P. emaijinata, P. diffusa, 

 and some other species ; and yet from the very expressive figures of Mr. Hancock, I am 

 inclined to believe in the existence of this character also in the present species. 



10. Plumatella ekyaiis, Allman. PI. VHI, figs. 6 — 10. 



Specific character. — Ccenoecium adherent, creeping, cells of uniform diameter; with a furrow 

 and keel. Calyx but slightly festooned. Statoblasts broad. 



Synonym. — 1850. Plumatella elegans. Allman, British Association Report, 1850. 



Iconography. — No published figure. 



Habitat. — On the under side of floating leaves in still water. Avoiding the light. 



Locality. — Millpond, Bandon Distillery, county of Cork, attached to the under surface 

 of the leaves of Potomogeton valans. 



I have as yet met with P. elegans only in one locality, and there it was by no means 

 abundant. It occurred upon the under surface of the leaves of Potomogeton natans in small 

 irregular patches, formed by a somewhat sinuous, branched, closely adherent tube. The 

 ectocyst is brown, sabellose in its texture, and with a well-marked furrow, which passes below 

 into a keel, and terminates near the orifice in a broad notcli-like space. Transverse septa 

 may be distinctly seen intersecting most of the cells near their origin. The polypides are 

 small, and the calyciform membrane exhibits scarcely a trace of festooning. The statoblasts 

 are elliptical, with a widely overlapping annulus ; they are narrower than those of P. repens, 

 but wider than the ova of P. emarginata, and present no tendency to the bean-shaped figure 

 of tlie latter. 



It was during the morth of August that I met with this species. 



