200 NEW-YORK FAUNA — MOLLUSCA. 



Anodon SUBCYLINDRACEA. 



PLATE XVI. FIG. 229. 

 Anodon subcylindracea. Lea, Trans. Am. Phil. Soc. Vol. 6, p. 106, pL 24, fig. 117. 



Description. Shell moderately small, elliptical, rounded at both ends, nearly cylindrical, 

 very inequilateral. Ligaments elevated : substance of the shell usually thin, but occasionally 

 solid. Beaks somewhat prominent, and minutely undulated at the tip ; basal margin very 

 slightly contracted. Anterior and posterior cicatrices confluent ; dorsal cicatrices not percep- 

 tible. Shell deep : cavity of the beaks shallow. 



Color. Epidermis deep brown, lighter towards the beaks, and without rays ; within, bluish 

 iridescent. 



Vertical axis, 1*1; transverse ditto, 2*2. 



I am indebted to Dr. Boyd for this species, which was obtained by him at Oak-orchard 

 creek, Orleans county, in 1837. I then had indicated it as probably anew species, but as I 

 find it published by Mr. Lea, have adopted his name. It occurs also in the Oswego river. 



Anodon ferussaciana. 



PLATE XVI. FIG. 230. 



Anodonta ferussaciana. Lea, Trans. Am. Phil. Soc. Vol. 5, p. 45, pi. 6, fig. 15. 



Margarita (Anodonta) id. id. lb. Vol. 6, p. 138. 



Description. Shell thin, subcylindrical, inequilateral, inflated, pointed at one extremity. 

 Dorsal margin curved immediately under the point of the beak ; basal margin regularly curved : 

 ligament rather short and thin. Beaks somewhat prominent, often decorticated, with two or 

 three small undulations at the tip. 



Color. Epidermis olive-green, with concentric shades of light green and obscure rays of 

 the same : within bluish white, iridescent ; tinged with salmon color under the beaks. 



Vertical axis, 1*4; transverse ditto, 2 '35. 



This delicate and beautiful shell was also communicated to me by Dr. Boyd, as a supposed 

 new species. It was obtained by that gentleman from the Erie canal, near Coldspring. It 

 was first described by Mr. Lea, from the River Ohio. The New-York specimens appear to 

 be of a lighter hue. 



P 



