408 Mr. A. H. Hassall on the genus Lepralia 



on shells, more particularly on Patella ccerulea ; it is a delicate 

 species, and the specimens found on this shell are usually very 

 perfect, owing no doubt to the sheltered position which it oc- 

 cupies in the root of Laminaria saccharina, on the frond of 

 which sea-weed it is also sometimes located. Of Lepralia ap- 

 pensa* there are several examples before me ; some on Patella 

 ccerulea, the majority on the roots of Laminaria diyitata and 

 L. saccharina, which are such great favourites with the Le- 

 pralia, and others on their laminae: and of L. ventricosa, two on 

 the smooth internal surface of a Pecten, and one on the rough 

 exterior of an Ostrea, The numerous specimens which I have 

 of Lepralia nitida, L. coccinea of Johnston, and L. linearis, 

 are all upon granite ; those of Lepralia auriculata and L. se- 

 milunaris upon shells ; and the following species, Lepralia hy- 

 alina, L. assimilis and L. diaphana, on either the root or frond 

 of Laminaria digitata or L. saccharina. Now the remark 

 which I have made with reference to Lepralia pediostoma may 

 be extended to the different species just enumerated thus va- 

 riously situated, for not alone are all the essential characters 

 of each of these species preserved, but I do not notice even 

 minor differences attributable to the dissimilarity of their 

 places of growth. The influence of locality, therefore, is so 

 slight as scarcely to be appreciable. 



Secondly, with reference to age. I have examined more than 

 two dozen specimens of Lepralia pediostoma and L. punctata, 

 as well as many of other species, and in all these the distinct- 

 ive characters of each species are preserved ; the walls of the 

 cells present the same appearances in each (excepting only one 

 species with transparent walls, L. hyalina), nor does the form 

 of the aperture differ in any material respects, and out of so 

 many specimens it may be fairly concluded that some are young, 

 while others are aged. In some species, especially the follow- 

 ing, Lepralia appensa, in which they are rarely absent, L. coc- 

 cinea and L. punctata, situated at each upper angle of most 

 cells are small triangular wing-like appendages, hollow, open 

 at the top, and communicating with the interior of each cell 

 below, one to each angle ; these alae are usually regarded as 

 abortive cells ; their presence is not constant, and may possibly 

 depend upon the age of the polypidoms. In the same specimen 



the last few days received a specimen of it from the Rev. David Lands- 

 borough, found at Stevenston, Ayrshire. Mr. Landsborough has also no- 

 ticed my L. pediostoma at the same place, making a second English locality 

 for the species. 



* This zoophyte is also met with on the English coast. It occurs at 

 Burnham, Norfolk, and specimens have been sent me from Jersey by Miss 

 Nolcken. 



