MALACOZOA. TROPIOPODA. LAMELL1BRANCHIATA. 277 



the beach, perforated in all directions. It is sometimes dredged 

 up in Salcomb Bay, detached from any other substance, so 

 that it does not seem to be a borer in all situations ; perhaps it 

 does not enter anything but limestone, which is not to be found 

 in this last place. A variety is highly glossed, with a resplen- 

 dent pearly hue." It is of this kind that all the specimens 

 which I have seen on the Aberdeenshire coast are. 



Found by me, in August, 1842, among shells on the beach, 

 near Aberdeen. It is occasionally not uncommon there, and 

 is one of the most beautifully delicate of our bivalve shells, in 

 this respect resembling Cryptodon flexuosus, and in form not 

 unlike Cyclas cornea, as Montagu has remarked. Found also 

 in September, on the Buchan coast, near Peterhead, by Mr. 

 Alex. Murray. 



Mya suborbicularis. Mont. Test. Brit. 39. 564. PI. 26. f. 6. Penn. 

 Brit. Zool. Ed. n. iv. 166. Kellia suborbicularis. Turk Brit. Biv. 

 57. PL 11. f. 5,6. Kellia suborbicularis. Flem. Brit. Anim. 430. 



2. Kellia rubra. Red Kellia. 



Shell ovato-rotundate, inequilateral, equivalve, convex, 

 glossy; with the valves moderately thick, little transparent, 

 obsoletely striato-sulcate concentrically ; the umbones small, 

 rather obtuse, a little curved ; the hinge with two small teeth 

 under the umbo in the right valve, a concave tooth and a re- 

 mote lateral in the other ; the colour deep purplish-red toward 

 the umbones, fading toward the margins, or hyaline-grey 

 tinged with purple, or purplish-white ; the inside deep purple, 

 glossy. Length from a twelfth to a twelfth and a-half, height 

 a fourth less. 



First observed by me, in January, 1843, among shell sand 

 from Ugie-mouth, and Cruden Bay, sent by Mr. Alexander 

 Murray. 



Cardium rubrum. Mont. Test. Brit. 83. PI. 27. f. 4. Kellia 

 rubra. Turt. Brit. Biv. 58. PI. 11. f. 7, 8. Kellia rubra. Flem. 

 Brit. Anim. 430. 



GENUS 2. LEPTON. 



Shell suborbicular, compressed, equivalve, nearly equi- 

 lateral, slightly open at the ends. Hinge of one valve 

 with a small medial prominent tooth, on each side of 

 which is a depression, succeeded by an elongated lamel- 

 liform lateral tooth, having a prominence at its umbonal 



