MUTULA 1355 



end obliquely truncate, rounded below ; anterior end narrowed, 

 rounded, very sligbtly cut away below ; base incurved to be- 

 hind the middle, cjuite full towards the posterior end; surface 

 with irregular growth lines ; epideniiis greenish or olive-green ; 

 nacre iridescent ; hinge edentulous, obsoletely crenulate in 

 front. 



Length 132, height 53 mm. 



Tropical Africa. 

 Iridina nilotica Sowerby, Zool. Journal, I, 1835, p. 53, pi. 11. — 



? Cailliaud, Yoy. a Meroe, 1826, pi, lx, fig. 12. — Audouin, 



Savigny, Icon. Moll. Egypt, 1827, pi. vii, fig. 2. — Crouch, 



111. Int. Lam., 1827, p. 17, pi. x, fig. i. — Deshayes, Tr. 



Klem.. 11, 1853, p. 219, pi. XVII, figs. 6. 7. — Chenu, Man., 



1859. 11. p. 148, fig. 727. — SowERRY, Conch. Icon., XVI, 



1868, pi. IT, fig. 4. 

 Platiris (Spatha) nilotica Lea, Syn., 1838, p. 33. 

 Mytilus niloficiis Wood, Ind. Test. Rev.. 1856, p. 207, pi. 11, 



sup. fig. I. 

 Mutela nilotica H. and A. Adams, Gen. Rec. Moll., II, 1857, 



p. 506.— Simpson, Syn., 1900, p. 904. 

 ? Mutela jonberti Bourguignat, Un. and In, 1886, p. 28; Icon. 



Mai. 1888, pi. xxiii, fig. I. 

 f Mutela visscri Bourguignat, Un. and Ir., 1886, p. 31. 

 Mutela vysseri Bourguignat, Icon. Mai., 1888, pi. xxiii, fig. 3. 



According to Sowerby this species is obliquely inflated be- 

 hind, but he does not give the diameter. The want of teeth 

 behind should distinguish it from exotica, and the hinge line 

 is more curved and the base fuller behind than in any of the 

 allied forms. 



\"ar. emini von IMartens. 



Lower in front and smaller, posteriorly ascending and pro- 

 portionately swollen, so that the deepening between the pos- 

 terior dorsal margin and the inflation extending from the 

 beaks to the posterior end is very small ; ventral margin 

 straight, not incurved ; height to length as 2-5. 



Length 114, height 45, diam. 34 mm. 

 Mutela nilotica var. emini von Martens, Besch., 1897, p. 253. 



— Simpson, Syn., 1900, p. 904. 



