430 Bulletin American Museum of Natural History [Vol. LIII 
Mutela rostrata (Rang). See below. 
Mutela simpsoni AncEy, 1894, Mém. Soc. Zool. France, VI, p. 233, fig. 8 (on p. 
234). Simpson, 1914, ‘Descript. Cat. of Naiades,’ p. 13856 = Mutela cuneata PRESTON, 
1910, Ann. Mag. Nat. Hist., (8) VI, p. 62, Pl. v, fig. 13. Simpson, 1914, ‘Descript. 
Cat. of Naiades,’ p. 1365. Shiré River, 3 kilometers south of Lake Nyasa and 
Karonga on Lake Nyasa. Allied to M. alata (I. Lea), according to Dupuis, 1923, Ann. 
Soc. Zool. Belgique, LIII, (1922), p. 81. 
Mutela singularis (Pallary) = Mutelina singularis Patuary, 1924, Mém. Inst. 
d’Egypte, VII, 1, p. 53, Pl. rv, fig. 17. Mahmudieh Canal, Lower Egypt. 
Mutela soleniformis Bourguignat. See p. 437. 
Mutela subdiaphana Boureuienat, 1883, ‘Moll. Fluv. Nyanza Oukéréwé,’ pp. 
- § and 17; 1887, Bull. Soc. Malacol. France, IV, p. 268. Nile. Apparently never 
described. 
Mutela welwitschit (Morelet) =Iridina welwitschit MoRELET, 1868, ‘Voy. Wel- 
witsch, Moll. Terr. Fluv.,’ p. 98. Murie River near Trombete (Golungo Alto), 
Angola. 
Mutela dubia (Gmelin) 
Plate XX XVIII, Figures 1, la, 1b, 2 
“Le Mutel’”’ Apanson, 1757, ‘Hist. Nat. Sénégal, Hist. des Coquillages,’ p. 234, 
Pl. xvi, fig. 21 (Senegal). 
Mytilus dubius GmEurin, 1791, in Linneus, ‘Syst. Nat.,’ Ed. x11, I, 6, p. 3363 
(based upon Adanson’s ‘‘ Le Mutel,” type locality: Senegal). 
Mutela dubia H. anp A. Adams, 1857, ‘Gen. Recent. Moll.,’ IT, p. 506; III, Pl. 
CxIXx, figs. 1 and 1a... Srmpson, 1900, Proc. U. S. Nat. Mus., XXII, p. 903; 1914, 
‘Descript. Cat. of Naiades,’ p. 1358. 
Iridina mutel Rane, 1835, Nouv. Ann. Mus. Paris, IV, p. 314. 
Mutela adansoni BOURGUIGNAT. 
Figures are here given to show the type species of Mutela.. Like 
many West African species, it is more closely related to Nilotic than to 
Congo forms. Most of the specimens show very weak teeth on the 
posterior half of the hinge, asin Pl. XX XVIII, fig. 1b, but in some these 
are not perceptible. They were noticed by that remarkably acute ob- 
server, Adanson. While moderately strong, this shell is rather thin. 
It is by no means more solid than Jridina exotica Lamarck, as stated 
by Simpson, but, on the contrary, very much thinner. The bluish to 
pinkish nacre is beautifully iridescent throughout. 
Length, 100 mm.; height, 40 mm.; diameter, 24 mm. 
Teeter) | 
Mutela rostrata (Rang) 
Plate XX XIX, Figures 1 and 2 
Iridina rostrata RanG, 1835, Nouv. Ann. Mus. Paris, IV, p..316 (type locality: 
‘Marigot de l’escale des Darmancoutz,” Senegal). _Potizz anp Micuaup, 1844, 
‘Galerie Moll. Douai,’ II, p. 147, Pl. tv1, fig. 1. 
aie nenteon Ei Fs LM BOOSO UE Sat ok POU Abeer oer Wer CLs case fet cm Seen Ok 
1This figure is cited with doubt, as it has st i 
MMe 1t has stronger and more numerous teeth on the hinge than any 
