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AHGA B07/DEJ:IA1:A Dall . 



Aroa bowdenlana Dall, 1898, Trans. 7/agner Free Inst. Soi., Phila- 

 delphia, vol. 3, pt. 4, pp. 622-625, pi. 55, fig. 12. 



Desoription .- "Shell STtsall, inflated, somewhat irregular, 

 verv inequilateral, the beaks almost posterior; dorsal slope con- 

 spicuous; its outer border with a stout keel and its sr^rface 

 somewhat excavated; beaks small pointed, prosop-^^rate ; cardinal area 

 wide lozenge-shaped, flattish, "ith a few grooves for the resilium 

 forming a small lozenge near the beaks; sculpture as in A. umbon- 

 ata, the imbrications dose and subnodulous; shell not alate in 

 front and v.ith the anterior margin nearly vertical from the hinge- 

 line; posterior end obliquely truncate, the basal angle most ex- 

 tended, the dorsal one forming nearly a right angle; anterior 

 teeth ten, posterior twenty-seven, v;ith no noticeable hiatus in 

 the line, the teeth resembling those of A. para~ina but proport- 

 ionately larger; interior smooth, the oosterior end with a few 

 flutings, the rest of the maro-in entire; the b;;ssal foramen nar- 

 row and its margins encroaching only moderately on the valves. 

 Ion, 15, alt. of hinge-line 6, of bealcs 8, rllara. f greatest post- 

 eriorly) 9 ra." 



"This O'M little shell is peculiar in being narrov/er near 



