268 MALACOZOA. TROPIOPODA. LAMELLIBRANCHIATA. 



Frequently taken up by the lines at Aberdeen, and some- 

 times cast on the beach ; found at Cruden by Mr. Alexander 

 Murray ; at Gamrie by Miss Macgillivray. 



Venus ovata, Penn. Brit. Zool. iv. 97. PI. 56. f. 56. Cardiura 

 striatum radiatum. Walker, Test. Min. Rar. PL iii. f. 82. 

 Cytherea ovata. Flem. Brit. Anim. 445. Venus pectimila. Lamk. 

 Syst. v. 592 ; Ed. 2. vi. 348. 



7. Venus triangularis. Triangular Venus. 



Shell subtrigonal, thick, opaque, smooth, with some faint 

 concentric strise, yellowish-white ; the umbones very promi- 

 nent ; in one valve three central teeth, and a lateral tooth, in 

 the other two central teeth and a curved lateral tooth ; the 

 inner surface glossy, white or yellowish, with the muscular 

 impressions moderate. Length about five-twelfths, height 

 nearly the same. 



Several valves found in shell sand, from the Bay of Cruden, 

 sent by Mr. Murray, in November, 1842. 



Venus triangularis. Mont. Test. Brit. 577. PI. 17. f. 3. Cyprina 

 triangularis. Turt. Brit. Biv. 136. PL 11. f. 19, 20. -Cyprina tri- 

 angularis. Flem. Brit. Anim. 444. 



GENUS 6. VENERUPIS. ROCK-VENUS, 



Shell equivalve, very inequilateral, convex, ovate or 

 elliptical, concentrically striated. Umbones small, ap- 

 proximated, curved forwards. Anterior slope nearly 

 straight, short, with a faint oblong impression. Hinge 

 moderately strong ; the right valve with three close 

 divergent teeth, of which two are bifid, an anterior 

 groove, and a posterior convex grooved ridge; left 

 valve with three close divergent teeth, of which the cen- 

 tral is bifid, an anterior and a posterior ridge. Ligament 

 external long, Muscular impressions moderate, submar- 

 ginal ; pallial impression invaded by a large obtuse sinus 

 parallel to the margin. 



This genus contains those elongated species of the 

 genus Venus of Lamarck which have three small ap- 

 proximated teeth in each valve, and which Sowerby has 

 proposed to unite with the species of Lamarck's genus 

 Venerupis. That name however, besides being awkwardly 

 constructed, is not applicable to the greater number of 



