306 MALACOZOA. TROPIOPODA. LAMELLIBRANCHIATA. 



Pholades, few or none of which have been seen there 

 since. Single valves of Pholas crispata, however, I have 

 myself met with, on the sands between the Don and the 

 Ythan ; and Dr. Fleming informs me that he has seen 

 valves of Pholas Candida on the same beach. 



1. Pholas crispata. Curled Piddock. 



Shell subovate, widely open at both ends, very convex ; the 

 valves rather thick, rounded behind, angulate before, with a 

 ridge from the umbo to the lower margin, the portion anterior 

 to which is marked with strong muricate concentric ridges, 

 and obsolete radiating grooves, the posterior with plain and 

 less prominent striae ; the infra-umbonal process linear, flat- 

 tened, curved; the colour dull white. Length about three 

 inches, height a third less. 



Single valves of this species occur not very unfrequently on 

 the sandy beach, from the mouth of the Dee to that of the 

 Ythan ; and are sometimes taken up from off Aberdeen by the 

 fishing-lines. I have not however seen the animal entire ; but 

 there is reason to believe that it occurs off the coast. 



Concha altera parte dimidiata, striis unvatun crispatis donata. 

 Lister, Anim. Angl. 192. PI. 5. f. 38. Pholas crispata. Linn. Syst. 

 Nat. 11 11. Pholas crispatus. Penn. Brit. Zool. iv. 77. PI. 40. f. 

 12 ; Ed. n. iv. 157. PI. 43. f. 2. Pholas crispata. Mont. Test. Brit. 

 23. Pholas crispata. Turt. Brit. Biv. 6. Pholas crispata. Lamk. 

 Syst. Pholas crispata. Flem. Brit. Anim. 456. 



2. Pholas Candida. White Piddock. 



Shell ovato-oblong, open at both ends ; the valves very thin, 

 fragile, rounded before, and less open there than at the an- 

 terior end, which is narrowly rounded ; the surface marked 

 with radiating elevated lines, decussated by concentric lines, 

 and papillate at the intersections ; the infra-umbonal process 

 linear, flattened, curved ; the accessory piece oblong ; the 

 colour white. Length about two inches, height nearly one. 



Found by Mr. Alexander Murray near Peterhead and at 

 St. Fergus. Dr. Fleming informs me that he has seen it, as 

 well as Pholas crispata, in masses of peat cast on the beach 

 near Don-mouth. 



Concha Candida. Lister, Anim. Angl. 193. PI. 5. f. 39. Pholaa 

 Candida. Linn. Syst. Nat. 1111. Pholas Candidas. Penn. Brit. 

 Zool. iv. 78. PI. 39. f. 1 1. Pholas Candida. Mont. Test. Brit. 24. 

 Pholas Candida. Turt. Brit. Biv. 10. Pholas Candidas. Flem. Brit. 

 Anim. 457. 



