>19 - 



Dim," (iJiiiilcer, 18i;l), 



T^-oe looallt:;^. - Antilles. 



Shell Itrce, thin, elonp-'ate-quadrate, clecidedlT/ inequilat- 

 eral, v/ell-irdTlatecl, Vv'ith a median shallow, broad depression; 

 rounded anteriorl;'j and -oosteriorl^-, the carve hroarler anterior- 

 ly; 'orcal and ventral rriarftins subparallel; antero-dorsal riars-in 

 shorter and with a slightly steeper slope; ven"-r 1 marp-in sli.?ht- 

 ly erarprinated nedially b*: the de-ore , area; iimhones low, ola.o- 

 ed at about the anterior third of the length; anterior and post- 

 erior carina broad, rounded, not differentiated from the general 

 convexity of the shell; surf-ce sculptujred v;ith irregxilarly dis- 

 posed increment als, occasionally emphasizen and fine, relatively 

 closely spaced oblique striations, beginning oii the anterior 

 carina, flexed upward over the posterior carina and continuing- 

 across the posterior slope j but more obsciire ; hinpre normal; ant- 

 erior muscle scar high, the posterior lower and lar>-er; Toallial 

 sinus e:-:tending to a line be: "^ '''' "^'"^ umbo, larr-ely confluent 

 below with the oallial line. 



I^imensions .- length, 48 mm.; alt., (umbonal) 19.5 mm.; 

 seraidiam., 6.5 mm. 



?.emar>s .- On the v;hole ti'.e -iov;den ?sa';rrosolen resembles Cr.e 

 Pliocene and Kecent oumiiip ianus , althoup-h none of the specimens 

 at hand are as lar~e as those fo\u-.d at later horizons. The 

 close soacinr;- of the oblique lines on the 3o\vden soecir.iens is 



