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ScGtion Argina Graj' . 

 AROA (AI^GirA) TOIEPIA Dall var. MI3R0TERA n. var. 



ScaiDharea (Argina) tolepla Dall, 1B98, Trans. Wagner ?ree Inst. 



Sci., Philadelphia, vol. 5, pt. 4, pp. 649-650, pi. 33, 

 figs. 7, 3. (ex parte). 



Description .- Shell small, well inflatecl, the greatest in- 

 flation and greatest height of the shell behind the me-'ian horizon- 

 tal, compressed in the distal pos tero-dor sal region; right valve 

 smaller, more rounded, low> r posteriorly than the left; antero-dor- 

 sal margin very short; rounded anteriorly ; "base sloping tov/ard the 

 posterior end; posterior lateral margin scarcely rounded below, 

 but CL-rvi^.g to meet the dorscl mar~ln; umbones tumid, broad; med- 

 ia.lly sulcatei, placed at about the anterior third of the length; 

 left valve sculptured with thirty-sis to thirty-eight strong radi- 

 al ribs; anterior and median ribs subrounded, separated by narrow- 

 er interspaces, and nodu].ated, the nodules being connected across 

 the interspaces by raised lines; posterior ribs low^r, flatter, 

 separated by interspaces of almost the same v/idth, and sm-ooth or 

 inconspicuo^isly nodulsted ; right valve with twenty-eight to thirty 

 sharply sculptured, obscurely nodulate''. ribs separated by deeply 

 channelled interspaces of the same v/idth or slightly wider; card- 



