MALAL'OZOA. TROPIOPODA. LAMBLLIBRANCHIATA. 339 



end ; the valves very thin, brittle, distinctly or deeply striated 

 concentrically, with stronger growth-lines ; the hinge with two 

 central and two lateral teeth in one valve, two central arid on 

 each side a groove with two parallel laminae, in the other ; 

 the exterior olivaceous brown, or inclining to green, or yellow, 

 in tands, the interior bluish. Length two-twelfths and a-half, 

 height two-twelfths. 



Found by me in the Summer of 1841, in the Inverury 

 Canal. 



Tellina amnica. Muller, Verm. Terr, et Fluv. ii. 205. Cardium 

 amnicura. Mont. Test Brit. 14. Cyclas amnica. Turt. Brit. 

 Biv. 250. PI. 11. f. 15. Cyclas palustris. Drap. Moll. Terr, et 

 Fluv. 131. PI. 10. f. 17, 18. Cyclas anmicus. Flem. Brit. Anim. 

 453. Pisidium anmicum. Gray's Turton, 286, 285. PI. 1. f. 5. 



FAMILY VI. VENERINA. P. 210, 254. 



GENUS 6. VENERUPIS. P. 212, 268. 

 Venerupis decussdta. Decussated Venerupis. 



Shell ovato-oblong, subrhomboidal, moderately com- 

 pressed, reticulated with divergent and concentric striae, 

 papillate behind, yellowish or reddish, with numerous 

 small, generally angular brown markings. Decmsdtus, 

 cut crosswise. 



Shell ovato-oblong, subrhomboidal, narrower or rounded 

 anteriorly, subtruncate behind, considerably compressed, rather 

 thick, reticulated with deep but narrow divergent and concen- 

 tric strise, leaving by their intersection small tubercular pro- 

 minences especially at the posterior end ; the frontal slope 

 short, with an oblong faint, obliquely striate depression ; the 

 three cardinal teeth in each valve close, small, divergent, erect, 

 the middle tooth cleft, the posterior slightly so ; the umbones 

 small, a little curved ; the inner surface glossy ; the siphonal 

 sinus oblong, large, extending obliquely to the middle of the 

 shell ; the exterior reddish- white, with numerous small irre- 

 gular brownish-red markings, darker and more numerous 

 toward the dorsal margin; the interior yellow, toward the 

 margin white. Length an inch and seven-twelfths, height an 

 inch and a-twelfth. 



The above description is that of an individual found alive, 

 in February, 1 843, by Mr. Alexander Beaton, it having been 

 brought up by a fishing-line, from off Aberdeen. It is the 

 only individual that has occurred to me. 



