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XXX. Observations on Two Species of Pholas, found on the Sea- 

 coast in the neighbourhood of Edinburgh. By JOHN STARK, 

 Esq. M. W. S. Communicated by Dr BREWSTER. 



* 



(Read 9fith March 1826J 



JL HE Natural History of the Pholades, so far as regards their 

 mode of burrowing in wood and stone, seems yet to be but im- 

 perfectly understood, though the Pholas was known to the an- 

 cients, and PLINY notices its phosphorescent quality *. RONDE- 

 LETiusf, JOHNSTON, and RUMPHIUS have figured several spe- 

 cies ; LISTER, among others, gives representations of three Bri- 

 tish species, the Pholas dactylus, Candida, and crispata ; and Sir 

 ROBERT SIBBALD, in his Prodromus, has three rude figures of 

 the dactylus or crispata, as Scottish shells. None of these au- 

 thors, however, attempted to explain how the Pholades exca- 



* " His natura in tenebris, remoto luminc, alio fulgore clarere, et quanto magis 

 humorem habeant, ludere in ore mandentium, lucere in manibus, atque etiam in solo 

 et veste clecidentibus guttis." PLIN. lib. ix. c. 61. 



f- " Hse in saxis latet, ut saxo undique contegatur, per foramen duntaxat exi- 

 guum et sensui vix patens aqua nutritus. Testis constat duabus longis, non in latum 

 extensis mytulorum modo, sed rotundis. Intus eadem fere est caro quae in mytulis." 

 ROND. de Testaceis, lib. i. p. 49. I strongly suspect, that RONDELETIUS has fi- 

 gured the Mytilus lithophagus under the title of Pholas ; and that subsequent writers 

 have been misled from not having seen his figures. The species of Pholas which he 

 delineates is given under the name of Concha alter a longa. Vide ROND. p. 23, 27. 



| " Hse concha juxta Hartlepool frequenter reperiuntur, et in lapidis cujusdam 

 cretacei foraminibus latitant ab ipso eorum ortu ; nam ex his eximi non possunt, nisi 

 prius lapis frangatur." LISTER, Anim. Ang. p. 172. 4 



