and GaslropoiL-' j'roiii the Falkland Inlands. G!50 



aiiteiioi- cartliiKil tootli, wlieio it considorably oveiliangs tlie 

 iiiterioi- of the shell ; interior of shell white. 



LoI)^^ 2"5, hit. 4*25 mm. 



dial). Port Stanley, Falklaiul Islands ; taken IVoni t!ie 

 stomachs of fish {A. G. Bennett). 



A great many speeimens of the above three species have 

 been opened, and in uearly every case they have been found 

 io bear a more or less number of pearly blisters ; sometimes 

 these occur not only on the inner surface of the valves, but 

 also on the hinge-plate, giving at first sight the idea that a 

 com[>licated system of teeth is exposed to view. 



Davisia'^ hennctti, sp. n. (Fig. 7.) 



Shell suborbicular, almost equilateral, rather solid, cream- 

 coloured, slightly iridescent, concentrically striate; umbones 

 not very large, prominent ; dorsal margin anteriorly arched, 

 posteriorly sloping ; ventral margin and anterior and poste- 

 rior sides rounded; right valve bearing an obsolete cardinal 

 tooth, a narrow, erect, anterior and a broader and curved 

 posterior lateral ; left valve bearing a small, slightly oblique, 

 pointed cardinal tooth, a weak anterior and a broader, much 

 stronger and curved posterior lateral; interior of shell white. 



Long. 3"5 (about), lat. 3"7o mm. 



Jlah. Port Stanley, Falkland Islands ; taken from the 

 stomachs of fish {A, <J. Bennett). 



Davibia concenirica, sp. n. (Fig. 8.) 



Shell small, subovate, moderately solid, white, coarsely 

 concentrically striate throughout ; umbones large and some- 

 what prominent ; dorsal margin anteriorly sloping, posteriorly 

 more gradually SO; ventral margin gently rounded, as are 

 also the anterior and posterior sides ; right valve bearing a 

 short, straight, rather weak cardinal tooth, an angular ante- 

 rior lateral and an elongate posterior lateral tooth, biangulate 

 in the median part ; left valve bearing a badly defined oblique 

 cardinal and somewhat elongate weak laterals on either side; 

 hinge-plates projecting more in the right than in the left 

 valve ; interior of shell wliite. 



Long. 2"25, lat. (nearly) 2'75 mm. 



TIah. Port Stanley, Falkland Islands; taken from the 

 stomachs of fish (^-1. G. Bennett). 



* Aun. & M<ag-. Nat. Hist. 1910, vul. v. p. 113. 



