A5:3A (SOAPHAROA) V/ORLEIII n. Gp. 



Description .- Shell niedimn-sized, moderately inflated, hec.vy, 

 eloiTgate; dorsal marg-in long, straight, angular at "both e--tremities ; 

 ■ujievenly romided anteriorly, subtrmie-ated posteriorly; ventral mar- 

 gin asyirane trie ally arcuate; umbones inflated, lor, rith a very faint 

 median sulcus; left valve se-.ilpturs'? with thirty- tv/o clear-cut, square 

 radial ribs of almost constant width thro^^.Q•hout, exce-ot in the ex- 

 treme anterior and posterior regi'^ns, flattened on the posterior 

 slope; interspaces narrov/er than the ribs; except on the posterior 

 slope the ribs and interspaces crossed by concentric raised lines, 

 sharp in the intersiaaces and nodulating the ribs; risTht valve vath 

 thirty or thir'.y- one lov/er and usually narrov/er radial ribs, seoa- 

 rated by interspaces of about the same width; concentric lines 

 prominent in the interspaces, but nodulsting only a few anterior 

 ribs; cardinal area narrow, with one or two liprament grooves; teeth 

 small and straight redially, longer at both eu'^s and slightly ob- 

 lique at the posterior end of the series; inner mar-rin with short, 

 deep crenulations. 



Dimensions .- Length, 25.5 m:'.; alt., 17 •:m.; seraidiam. , 8.2 

 mm.; length of hinge, 18 nim. 



Remarks.- A. v;ordeni is characterized by its rather elongate 



