204 Description of a New Species of Plumatella. 



been the discovery of a species of Plumatella in great abun- 

 dance, in tlie quarries at E-ichmond, and I bave no doubt 

 that many others will ere long be added to the list. 



Plumatella Aplinii, n. sp. 



Csenseciumdichotomouslyor irregularly branched, creeping, 

 cells expanded upwards, mouth oblique, oval, with the 

 anterior lip pointed ; a strong ridge running along the front 

 of the CEensecium, and extending entirely or partly up the 

 cells; no furrow; tentacles, sixty; statoblasts elongated. 



Locality : On stones in old quarries at Richmond, on tim- 

 ber in the lagoon in the Survey Paddock, and on a stump 

 in the lagoon in the Botanic Gardens. — C. D^Oyley H. 

 Aplin, Esq. 



This beautiful polyzoon occurs in masses of various extent, 

 in some specimens covering several square inches. The 

 ceensecium is irregulary branched, sometimes leaving wide 

 interspaces, at other times densely covering the object to 

 which it is attached. It is usually closely adherent, but 

 occasionally the extremities of the branches are free and 

 semi-erect. On the front of the branches of the csensecium 

 there is a continuous prominent keel or ridge, which also 

 extends up the cells. The cells are short, expanding towards 

 the orifice, so as to be in some cases almost funnel-shaped ; 

 the mouth is oblique, oval, and frequently, from the con- 

 tinuation of the ridge, pointed anteriorly. There is no groove. 

 Only free stato-blasts have been observed ; they are of an 

 oblong elliptical form, with a wide annulus. 



The characters presented by this species are so well marked, 

 that it may at once be readily distinguished from all pre- 

 viously known. Its nearest ally is probably P. emai-ginata, 

 Allm., with which it agrees in the presence of a ridge, and in 

 the elongated stato-blasts ; but differs in the form of the cell, 

 and in the absence of the furrow at the cell-mouth, and in 

 the number of the tentacles. 



