Mr. A. Murray on a marked variety 0/ Patella vulgata. 213 



but there remains one which is very characteristic of it, and 

 which is peculiar to itself, viz. its rich- coloured spatula, generally 

 brownish -orange or yellowish-orange, rarely cream-coloured, 

 reminding one of the glowing interior of some of the South Sea 

 species. This character seems constant, and is readily recog- 

 nizable : in some rare cases the colour is comparatively pale, 

 but in the palest there is always a richness both of colour and 

 texture, which shows as great a difference between it and the 

 others as there is between cream and skimmed milk. 



Dr. Knapp would appear not to have been the only person 

 whom the peculiar characteristics of this shell have struck, for 

 Forbes and Hanley mention that Mr. Alder states " that in some 

 parts of England he had seen this Limpet {athletica) range much 

 higher up between tide-marks, and had noticed on the southern 

 coasts an intermediate form between this and vulgata, which looked 

 very like a hybrid." 



Whether Dr. Knapp's shell is the species which looked to Mr. 

 Alder like a hybrid, I do not know, but think it very probable 

 that it may be. If it is so, I do not imagine that by comparing 

 it to a hybrid, Mr. Alder meant to propound that it was a hybrid, 

 but merely that it possessed characters peculiar to both its allies ; 

 and so far he would be right. But a careful examination of a 

 sufficient series of the different forms, &c. assumed by the spe- 

 cies of Patella will not, I think, warrant us in holding it to be 

 more than a variety. The only strongly-marked features peculiar 

 to itself depend upon colour ; and although colour, when asso- 

 ciated with other pretty constant features, may be admitted as a 

 character in some genera, we can scarcely admit it as such in 

 Patella, where the variation of form and colour is very great, 

 considering the restricted scope the simplicity of its outline 

 affords. If it is not a distinct species, then the proper species 

 to which to refer it as a variety is undoubtedly vulgata. A very 

 marked and easily recognizable variety it certainly is; but, 

 as Dr. Greville has suggested to me, there are other varieties 

 not much less marked; for instance, the high, conical, peaked 

 form, characteristic of the species found at Inverary, and still more 

 so the deep leaden-coloured variety, which invariably exhibits a 

 margin almost black. These to my mind are not so striking as 

 the present, and, moreover, are varieties which are not confined, 

 as I believe this to be, to Guernsey and Jersey, and possibly the 

 south of England. Still the existence of so great variations 

 renders the possibility of others still greater not unlikely, and 

 I therefore have, on the whole, come to be of opinion that the 

 shell in question is merely a variety of the Patella vulgata, which, 

 for convenience of future reference, Dr. Knapp proposes to call 

 Patella vulgata var. intermedia. 



