102 CONCHIFERA. DIMYAIRA. 



rior slope flattish, and its margin spinous. f inch long. Inha- 

 bits Indian seas. Chem. vi. pi. 25, fig. 248. 



** Margin of the valves distinctly crenated or dentated. 

 D. rugosa, Lin. Shell wedge-shaped, gibbous, and wrinkled at the 

 posterior end ; margin crenated ; hinge without lateral teeth, and 

 the cartilage cleft ovate ; colour purplish, with paler transverse 

 bands, f inch long, and 1^ broad. Inhabits American seas. 

 Chem. vi. pi. 25, fig. 250. 



D. denticulata, Lin. Shell ovate wedge-shaped, with longitudinal 

 striae and intermediate dots ; anterior slope transversely wrink- 

 led ; margin toothed ; colour whitish, radiated with purple ; in- 

 side purple. 7 lines long, and 10 broad. B Penn. Brit. Zoo/, iv. 

 pi. 58, fig. 2. 



D. Meroe, Lam. {Venus, Lin.) Shell ovate- trigonal, compressed, 

 with parallel transverse striae, and reticulated purple lines ; ante- 

 rior depression excavated. 1 inch long. Inhabits Indian seas. 

 Lister, pi. 377, fig- 221. 



D. scripta, Lam. Shell ovate, subcompressed, smooth, waved with 

 purple transverse lines ; anterior depression excavated ; margins 

 acute. 8 lines long. Indian seas. Chem. vi, pi. 26, 261-265. 



D. trunculus, Lin. Shell oblong-wedge-shaped, glossy, minutely 

 striated longitudinally, and the margin crenated ; colour generally 

 yellowish white, with bluish or darker coloured transverse bands, 

 and two or three paler longitudinal rays. 6 lines long and 12 

 broad. European seas. B. Pen. Brit. Zoo/, iv. pi. 58, fig. 1. 

 This is a very plentiful species on the beach at Portobello, near Edinburgh. 



Gen. 29. LUCINA, Lam. Venus, Tellina, Lin. 

 Shell suborbicular, inequilateral, with the beaks small, pointed, 

 and oblique ; two primary divergent teeth, of which one is 

 bifid, but varying with age ; lateral teeth two, the posterior 

 nearest the primary ones ; two distant muscular impressions, 

 the posterior one prolonged. 



The hinge of this genus, though variable, has generally two diverging primary 

 teeth, of which one appears as if divided in two. These teeth are effaced, or disap- 

 pear with age in some of the species ; in one they are not found at all. The lateral 

 teeth are found in most. All have the ligament exterior. 



L. Pennsylvania, Lam. ( Venus, Lin.) Shell suborbicular, slightly 

 ventricose, thick, white, with transverse membranaceous striae,, 

 and a longitudinal furrow on the anterior side. 1^ or 2 inches 

 long. Inhabits West India seas Lister, pi. 305, fig. 138. 



L. radula, Lam. (Tellina, Mont.) Shell orbicular, convex, white, 

 with numerous concentric raised striae, and shallow broad inter- 

 vening spaces. 1^ inch in diameter. Inhabits British coasts. B. 

 Mont. Test. pi. 2, fig. 1, 2. 



L. carnaria, Lam. {Tellina, Lin.) Shell suborbicular, smooth, 

 flesh-coloured within and without ; marked with minute, oblique, 

 reflected striae, f inch long. Inhabits European seas. Wood's 

 Conch, pi. 40, fig. 4, 5. 



