90(i;ica|V^ ,c» ,tl<p loyf,er ^j^e, anql on tlip .ypRfr side extended 

 to ,the |Si^mni,it ,,of ,pe if^Rer^tViTP .W}lvi .a,.tj;ansy|efsely ridged 

 puriace. ' -" ' 



Mean divergence .about 8p° ; length 3^ ipph ; breadtk .2 

 inch; i|ength pf^pji^e .Q9.inch. 



Station. — Our specimens were found mostly on the short 

 suckers, which were growing up thickly beneath the mangroves, 

 near high water mark. ' 



Habitat. — Panama ; C. 3. 4- ' 



We collected 7^ speQinieps two and , qne-half miles east of 

 Panama. 



311. Auricula ^infrequens. Nor. sp. 



Shell ellipsoidal : brown, with a pale ill-defined, ppirj^li band ^a 

 little below the sutur,e : ,yvith fine strise^of growth : apex acute : 

 spire with the outlines moderately curvilinear: whorls six, 

 obtusely shouldered, with a de,ep suture ; last whorl compressed : 

 aperture subelliptical, rather wide : labrum very thin : with two 

 plates, of which ppei,is,^t^t}]jp pnteripr.p^rt of the aperture and 

 is oblique, and the other is transverse and is at the middle. 



Mean divergence about 80° ; length .23 inch ; breadth .15 

 inch ; length of ^pii:e >1 ifl.ch. 



Station. — Under, stones, near high water mark. 



Habitat. — Panama ; 0. B. A. I 



We collected 6 specimens, in pompany^y^ith P^ipes angulata, 

 at the base of the sea wall of Panama. ' 



312. Auricula Panamensis. :,Nor. sp. 



Shell long ovate: blackish red throughout ^^ except that the 

 plaits are white : smooth and shining, with a few microscopic 

 spiral stri89 near the apex : apex acute : spire with the outlinea 

 verv curvilinear over the middle whorls, and nearly rectilinear 

 on the lower whorls: whorls eight, convex, imbricately appressed, ; 



JULY, 1852. 53 Am. Ltd. NiT. Hist. ' 



