— 62 — 



side though sloping above is rounded and not at ail rostrate below; the 

 muscular scars are well impressed on both sides and the interior of the shell 

 is generally whitish. 



Long. 32, lat. 62.5, diam. 21.75 """t^- 



Hab. — Shire River. 



Spatha mwayana sp. n. — PI V, fig. 15. 



Shell elongatel}' ovate, solid, covered with a rather thin and glossy 

 reddish-brown periostracum which becomes thicker and somewhat finel)' 

 scabrous towards the posterior side, marked with concentric growth lines 

 and traces of very fine, radiate striae: umbones small, not promineut; dor- 

 sal margin scarcelj' arched, sloping; ventral margin slightly contracted in 

 the médian région, otherwise straight; anterior side gently rounded ; poste- 

 rior side sloping above then somewhat sharply rounded and again sloping 

 below; anterior scars ovate, both thèse and the posterior scars well impressed; 

 palleal line well marked, almost parallel with the ventral margin, posteriorh" 

 rather abruptly rounded; interior of shell pinkish, iridescent, marked with 

 radiate striae. 



Long. 39.5, lat. 70.75, diam. 17.5 (Type). 



Auother spécimen : Long. 42.5. lat. j8 mm. 



Hab. — Mwava, shores of Lake Nvassa, in German Territory. 



