NO. 1205. SYNOPSIS OF THE NAIADES SIMPSON. 903 



dorsal scars an irregular row, extending downward and forward; 

 muscle scars irregular. 



Animal having the palpi longer than wide, not united; mantle mar- 

 gin united as far as the foot, so that the branchial and anal openings 

 are closed ; outer branchiae united to the mantle to the extremity ; inner 

 entirely united to the foot; foot tongue shaped, somewhat produced 

 anteriorly. Iridina ccclestis Lea (Troschel.) 



(Group of Mutela exotica.) 

 Shell elongate, rhomboid, wider and subtruucated behind, subsolid. 



t MUTELA EXOTICA Lamarck. 



" Iridina exotica LAMARCK, An. sans Vert., Y I, 1819, p. 89; *Enc. Me'th., II, 1827, 

 p. 147, pi. cci v, fig. 1, 16 ; * STARK, Nafc. Hist., II, 1828, p. 88.* LEA, Syn., 1836, 

 p. 56. * HANLEY, Biv. Shells, 1843, p. 225. * CATLOW and EEEVE, Conch. 

 Norn., 1845, p. 68.* SOWERBY, Couch. Icon., XVI, 1868, pi. i, fig. 2.* CLES- 

 SIN, Conch. Cab. Ano., 1875, p. 231, pi. LXXI, fig. 1. 



* Anodonta exotica BLAINVILLE, Man., 1825, p. 538, pi. LXVI, fig. 3. 



* Platiris (Iridina) exotica LEA, Syn., 1838, p. 33; 1852, p. 54; 1870, p. 88. 



* Plciodon cxoticm PJCTEL, Conch. Sam., Ill, 1890, p. 188. 



* Iridina dongata SOWEKBY, Rec. and Fos. Shells, VII, 1821, fig. I. 1 * OKEN, Isis, 



1834, p. 458.* SOWERBY, Couch. Man., 1839, fig. 150.* SWAINSON, Tr. on 

 Mai., 1840, p. 286, fig. 60. * REEVE, Conch. Syst., I, 1841, p. 122, pi. xcn. 

 * HANLEY, Biv. Shells, 1843, p. 225.* CATLOW and REEVE, Conch. Nom., 1845, 

 p. 68.* SOWERBY, Conch. Icon., XVI, 1868, pi. i, fig. 1. 



* Platiris (Spatha) clongata LEA, Syn., 1838, p. 34. 

 *Hutcla elongata P.ETEL, Conch. Sam., Ill, 1890, p. 187. 



* Iridina striata OKEN, Isis, 1834, p. 458. 



* ? Mxtela soleniformis BOURGUIGXAT, Esp. Ouk., 1885, p. 25. *PELSENEER, Bull. 



Mus. Belg., IV, 1886, p. 109.* BOURGUIGNAT, Icon. Mai., 1888, pi. xxn, fig. 

 2. * VON MARTENS, Besch., 1897, p. 254. 



* ? Mutela bridouxi BOURGUIGNAT, Un. ct Ir., 1886, p. 25; * Icon. Mai., 1888, pi. 



xxn, fig. 1. 



Tropical Africa. 



t MUTELA DUBIA Gmelin. 



Le Mutel ADANMON, Hist. Nat. du Sen., 1757, p. 234, pi. xvii, fig. 21. 

 *Mytilu8 dubia GMELIN, Syst. Nat., 1788, p. 3368. 2 



* Anodonta dubia Bosc, Hist Nat. Coq., Ill, 1824, p. 144. 

 *Platiri8 (SpatJta) dubia LEA, Syn., 1852, p. 55; 1870, p. 89. 



* Mutcla dubia H. and A. ADAMS, Gen. Rec. Moll., II, 1857, p. 506, pi. cxix; III, 



figs. 1, la. *CLESSIN, Conch. Cab. Ano., 1873, p. 194, pi. xxv, fig. 3. 

 *P.ETEL, Conch. Sam., Ill, 1890, p. 187. 



* Iridina dubia CHENU, Man., 1859, II, p. 147, fig. 726. 



* Mytilus dubius DILLWYN, part, Cat., I, 1817, p. 318. * Wooi>, Ind. Test, rev., 



1856, p. 69, pi. xn, fig. 36. 



West Africa. 



1 1 agree with Lea that this = exotica. The teeth are not strongly developed. 



-Gmelin refers to Adauson's figure. Dillwyn evidently has Ginelin's species and 

 Cristaria plicata from China confounded. Two or three of these so-called species of 

 Miitela are very close, and large series from different localities would probably show 

 that they run together. There is much variation in the form find the develop- 

 ment of hinge tubercles, even in a single species from a given locality. 



