404 Mr. J. Alder on Lottia virginea. 



Glints, Durham ? Banks of the Swale, Richmond, Yorkshire. Wat- 

 son Herbarium. On a rising ground beyond Robin Hood Inn in the 

 road to Kingston-upon-Thames. Eng. Bot. 



In conclusion, I would mention a suggestion of Mr. H. C. 

 Watson's, which to my mind is of very primary importance, 

 and the resolution of which by cultivators of our British 

 plants will go far to settle the question of the real claims of 

 E. brachycarpum to the rank of a species. I will quote Mr. 

 Watson's own words : " It may be worth ascertaining whether 

 luxuriance at root does not enlarge the leaves and shorten 

 the capsule. Fruit is often imperfect when roots are strong 

 and well nourished, especially in creepers." In the roots of 

 the plants forwarded to me by Mr. Jorden, I did not observe 

 any perceptible difference of luxuriance ; but Mr. Jorden's 

 observation, that E. brachycarpum never produced fertile 

 seeds, so confirmatory of Mr. Watson's remark, must be care- 

 fully borne in mind, as it goes far to render such luxuriance 

 imder cultivation very probable. 



W. A. Leighton. 



\)ec. 24, 1811. 



XLIX. — Remarks on Lottia virginea. By Josh. Alder, Esq. 



Some misunderstanding has lately arisen concerning the 

 characters and synonyms of the little mollusk whose shell 

 has been long known to British conchologists as the Patella 

 parva of Da Costa. This species was referred by Matonand 

 Rackett, and by Montagu, to the Patella virginea of Muller ; 

 an opinion which was generally adopted by succeeding authors, 

 until Dr. Johnston, in a short article published in the second 

 volume of the ' Magazine of Zoology and Botany,' gave some 

 reasons for supposing it to be incorrect. Audouin and Milne 

 Edwards having stated that the animal of the *' Patellesroses^' 

 found in the English Channel differed entirely in the structure 

 of the branchiae from the true Patellce, Dr. Johnston was in- 

 duced to examine the Patella virginea of our shores, and " I 

 soon satisfied myself," he says, " that those found on the coast 

 of Berwickshire at least were formed like the true Patella, the 

 cloak of the animal being ciliated all round with a fringe of 

 short equal filaments. The accuracy of this observation I 

 have recently had occasion to confirm in company with my 

 friend Mr. J. Alder. It follows, therefore," he adds, " that 

 the shell usually called Patella virginea by British concholo- 

 gists is not that so named by Muller, but is probably his Pa- 

 tella tessellata, in which the margin of the cloak is ciliated." 

 The opinion that our species is the Patella tessellata of Mul- 



