1 - 



r: ■ ';v/eeii the ' .-.'inae vSliglitl^ t 



tho margin t"he truncation; e ternal ' iii-- 



o\:a aonceii ■"■ , '" '">" --^f the shell 

 h ;vi.. ir e's*-^ tuiokeael and turned bov/ard tlie ai;ib9, e::cept 



near the liuiule, rlth, on their ventral , ils, oep;- 



■:-ic.L-:icb aoes hut alt t- less •'■;ell 



radials on the shorter ' :. de o:" is; along a 



■.-^.i^-r.l li;-'- "i,:.ri i" ■!:" :,-^ r^^.ln-|^ of the Shell '"~ - ■ '■■• T'i'!^'^ 



■; -•-: • ?rd t" oral laargin and finely; ^ 'l;,.' arenulat- 



cd, from ti-e en"', a o:'' each erentilation iiarrov;, ' ials exten'''.ing 



aero'. . " - • i ? .> -^ •-■ . ■ • -q nor--.?!, 



tlie 1' rdiiial strong aaid the left ee cardinal 

 ohscurel, 



DiTiensions .- "■;■ '"' , ^"".' ' ''. ; '•, ■ •; '^iar:;., 

 8 rjm. 



^iemar>3 .~ Tith regjard to numerical re pi 



species almost riv?1 s 'J, f Liroph or a ) he"' ^ ^v '^ onx , b^^'' '"' ■ .-•''■-o-^-_ 



sc'^'ers are more constant. Ihe nuraher of ribs oi .1 tei'^ 



milliraeters of the shell -^s from - - shells 



are more roinded in O'^'""" ' ' _ ' .. '\ ' ■""'"' — ii. • 

 crenulate'' over th 11. 



£, sa^kinsi i ized h;^ '" ' 1 Titerior trun- 



-■;*■-•- " " ifference in '■''■- --■'■■■■• "^^'^■^' "'■'' 



