Shells from the Falkland Islands. 221 



Cliilian coast and from the present locality ; in every case 

 the specimens from the continentnl area were of a whitish or 

 ])a!e yellowish tint, while those from the Fiilkland Inlands 

 were invari;ibiy ot a dark brown colour ; th ; la lirin;^ colour- 

 lines which occur in both forms are considv rably more 

 coiispiciinns in the jiresent variety, but in all other respects, 

 aj)art from colour, both the continental and island shells do 

 not appear to differ. 



Nacella falklandica, sp. n. (Fig. G.) 



Sliell large, elongatel}' ovate, slightly laterally compressed, 

 moderately thin, dorsally arched, with very posterior and 

 somewhat curvedly overhanging a[)ex, pale greenish olive, 

 painted, especially posteriorly, with streaks and blotches of 

 chestnut, sculptured with broad radiate costuUe, crossed by 

 tine, closely set, and very wavy concentric stiice ; maroin 

 coarsely crenellate by the terminations of the radiate costulae ; 

 interior of shell polished, shining, yellowish white, closely 

 rayed and mottled with chestnut-brown. 



Alt. 16, diam. maj. 42'0, diam. min. 21*75 mm. 



JJab. Falkland Islands (.4. G. Bennett). 



Helcioniscus bennetti, sp. n. (Fig. 7.) 



Shell small, thin, brown, ovate, with subcenfral nucleus, 

 anteriorly somewhat gently slo[)ing, very slightly convex, 

 posteriorly steeply sloping, slightly concave, sculptured with 

 multitudinous, rounded, radiating riblets crossed by rather 

 fine, concentiic, scabious ridges; margin of shell reddish 

 chestnut, slightly crenellated by the terminations of the 

 radiating riblets; interior of shell bronze, shading to 

 yellowish brown ; spatula large, well defined, ovately 

 rectangular. 



Alt. 8'5, diam. maj. 25 mm. 



Hab. Fort Stanley, Falkland Islands (A. G. Bennett). 



Modi'olarca ben teiti, sp. n. (Fig. 8 ) 



Shell rather convex, somewhat rectangular, covered with a 

 dark chocolate periostraciun ; dorsal margin almost straight; 

 ventral margin very slightly rounded; anterior side also 

 very slightly rounded ; posterior side ])roduced and obtusely 

 rounded; uinb aies very anteriorly situate, small, not promi- 

 nent ; right valve bearing an elongate and upwaidly curved 

 cardinal tooth, left valve an elongate, somewhat erect, 

 nodulous, cardinal tooth ; interior of shell dark livid purple. 



