FRESHWATER AND LAND SHELLS. 45 



Anodonta cylindracea. Plate XIII. fig. 40. 



Testa cylindracea, injlatd, valdh transversa, ino&quilaterali ; valiiulis tenuibus; natibus sub- 

 prominulis ; epidermide tenebroso-fuscd, radiata ; margarita carulea. 



Shell cylindrical, inflated, very transverse, inequilateral ; valves thin ; beaks some- 

 what prominent ; epidermis dark brown, radiated ; nacre blue. 



Hab. River Medellin, near Vera Cruz. Dr Burroiigh. 



My Cabinet. 



Cabinet of Dr Burrough. 



Diam. -9, Length 1-3, Breadth 2-3 inches. 



Shell cylindrical, inflated, very transverse, inequilateral, flattened on 

 the umbones, subbiangular behind ; umbonial slope rounded ; substance 

 of the shell thin ; beaks somewhat prominent ; ligament long and slen- 

 der ; epidermis dark brown, with numerous capillary rays over the 

 whole disk ; anterior cicatrices confluent ; posterior cicatrices conflu- 

 ent ; dorsal cicatrices not perceptible ; cavity of the shell large ; cavity 

 of the beaks small ; nacre blue and iridescent. 



Remarks. — Two specimens only of this were sent by Dr Burrough. 

 The one figured appears to be mature and in a good state ; the other 

 is young and imperfect. In outline it differs from any species within 

 my knowledge. In the nacre it somewhat resembles the A, tenebri- 

 cosa (nobis), but is a much thinner and more transverse shell. The 

 deposit of epidermal matter in the interior, gives it a very clouded 

 appearance. It is highly iridescent on the posterior portion of the 

 nacre. 



Anodonta salmonia. Plate XIV. fig. 41. 



Testa ellipticd, transversa, inflata, valdh incBquilaterali ; valvulis tenuibus ; natibus pro- 

 minulis; epidermide tenebroso-fusca ; margarita colore salmonis tincta, infernh cctrulea. 



Shell elliptical, transverse, inflated, very inequilateral ; valves thin; beaks somewhat 

 prominent; epidermis dark brown ; nacre salmon colour, bluish along the base. 

 VI. — M 



