Shells from tie Falkland Islands. 223 



Saxicava subantarctica, sp. n. (Fig. 12.) 



Shell inequivalve and inequilateral, elongately subrec- 

 tangular, wliitish except where covered with a menibianaceou3 

 reddish periostracum, marked with coarse irreguhir con- 

 centric ridges ; dorsal margin arclied anteriorly, scarcely 

 sloping posteriorly ; ventral margin a little contracted in the 

 median region, otherwise rather straight ; anterior side angled 

 above, sloping below ; posterior side angularly rounded 

 above, bluntly rostrate below ; ligament rather lung, fleshy; 

 umbones not prominent, much eroded ; hinge-plate edentu- 

 late ; interior of shell whitish. 



Long. 8'5, lat. 17 nun. 



Hub. Falkland Islands (^1. G. Bennett). 



Mytllimeria falklandica, sp. n. (Fig. 13.) 



Shill o\ ately rectangular, posteriorly gaping, thin, covered 

 with a thin, brownish-yellow, membranaceous periostracum, 

 which slightly overlaps the margin of the shell ; both valves 

 concentrically creased and radiately sculptured with mode- 

 rately fine and distant ridges ; dorsal margin nearly straight; 

 ventral margin gently rounded; anterior side rather angu- 

 larly rounded; posterior side ])roduced, obtusely rounded; 

 umbones small, very anteriorly situate, not prominent ; 

 interior of shell nacreous and marked with fine scratch-like 

 grooves, esj)ccially towards the uinbonal region, which 

 correspond to the radiating ridges on the outer surface of the 

 shell. 



Long. 10*5, lat. 17'25 mm. 



Eab. Falkland Islands {A. G. Bennett). 



EXPLANATION OF PLATE IV. 



Fig. 1. Natica falkUtncUca, sp. n., nat. size. 



Fig. 2. subantarctica, sp. n., uat. size. 



Fig. 3. Photinula solidula, C. & P., var. depressa, var. n., nat. size. 



Fig. -1. AcDxea itiquilinus, sp. n., X 2. 



Fig. 5. pcrconica, sp. u., nat. size. 



Fig. 6. Nacella falJdatidica, sp. u., nat. size. 



Fig. 7. Helicioniscus beniietti, sp. u., nat. size. 



Fig. 8. Modiolarca benjietti, sp. n., x 2. 



Fig. 9. Cyamiwn copiosum, sp. n., X 2. 



Fig. 10. cuneatum, sp. n., X 2. 



Fig. IL staiileyense, sp. n., x 2. 



tig 12. Saxicava subantarctica, sp. n., nat. size. 



Fig. 13, Mytilimeria falkktndica, sp. n., nat. size. 



