

L38 PALEONTOLOGY OF NEW YORK. 



Pttchopteria Eudora, n. sp. 



PLATE LXXXV, FIG, !'. 



Shell of medium size, rhomboidal; body narrow, elongate-ovate, oblique at an 



angle of about 30° with the hinge-line; length nearly twice the height ; 

 ante-byssal margin oblique, curving into the long, shallow sinus; base 

 broadly curved ; posterior end acutely recurved. 



Lett valve gibbous above, convex below. Right valve unknown. 



Hinge-line straight, greater than the height of the shell. 



Beak a little in front of the anterior third of the hinge directed forward, 

 rising above the cardinal line. Umbo narrow and gibbous, subtending a 

 very acute angle. 



Anterior end small, limited by a well-marked and oblique byssal depression ; 

 extremity acute. The distance from the byssal sinus to the cardinal margin 

 is one-half the greatest height of the valve. Wing joining the body one- 

 fourth its length above the posterior end ; the shallow furrow and fold defin- 

 ing its limits are not strongly marked ; margin obliquely truncate ; extremity 

 not produced. 



Tesi thin, marked by radii which are very fine and undulating on the 

 body and wing, while they are obsolete on the anterior portion; these are 

 cancellated by tine concentric stria', which on some portions are fasciculate, 

 and very conspicuous on the anterior end. 



Interior unknown. 



The specimen described has a, length of 36 mm., height 20 nun., and 

 hinge-line about 23 mm. 



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This species bears considerable resemblance to P. Eucratc, but its anterior end 

 is proportionally narrower, and it may also be distinguished by the absence of 

 a continuous angularity along the body, the more abrupt recurving of the post- 

 basal margin, the more oblique truncation of the wing, and the less conspicu- 

 ous surface markings. It differs from P. Spio in its more gibbous umbo and 



