MUTFJ,A 1357 



low ; base nearly straight ; surface concentrically striate and 

 furnished in front with a few widely spaced, radial, narrow 

 grooves ; epidermis }ello\vish-green, iridescent ; hinge slender, 

 smooth ; nacre splendid rose-color, iridescent, whitish on the 

 border. 



Length 72, height 35, diam. 28 mm. 



Shire and Karonga rivers, near Lake Nyassa. 

 Mutela simpsoni Ancky, Mem. Soc. Zool. de Fr., VII, 1894, 



p. 233, fig. 8. — Simpson, Syn., 1900, p. 904. 

 Mittela alata var. s'unpsoni von Martens, Besch., 1897, p. 253. 



— Gkrmain, Arch. Zool. Exp. et Gen., (5), I, 1909, p. 58. 



Remarkable for the rather conspicuous radial furrows on 

 the front half of the disk. The splendid rose-colored nacre 

 should be a distinguishing character. 



Mutela iiargeri E. A. Smith. 



"Shell irregularly triangular, alate, much compressed and 

 very inaequilateral, white, covered with an olivaceous periostra- 

 cum, striate with lines of growth and everywhere painted with 

 very fine, close, radiating, greenish lines ; anterior side short, 

 obliquely curved, posterior side very broad, obliquely trun- 

 cated above ; ventral margin widely curved ; valves thin, slight- 

 ly raised or ridged in the middle between the umbo and the 

 posterior side : interior of shell white, pearly, iridescent ; hinge 

 simple ; ligament narrow, elongated, occupying the whole mar- 

 gin ; anterior muscular impression not deep, irregularly round- 

 ed ; posterior obscure, superficial. 



Length 104, height 68, diam. 16 mm." (Smith). 



Type locality, Lake Mweru. 

 Mutela hargeri E. A. Smith, Proc. Mai. Soc. London, VIII, 



1908, p. 14, text-fig. 



"Only a single left valve of this species was obtained. The 

 diameter above given is supposed to be that of a complete spec- 

 imen. The radiating lines are hair-like and scarcely noticeable 

 tmless specially looked for. Spatha alata Lea, from Lake 

 Nyassa, is an allied species, but less winged." 



