I402 LEILA 



The synonymy of the form described above seems to be 

 somewhat involved. d'Orbigny used the name Iridina esula 

 in 1835 for a species, vvJiich he credits to Jan, and states that 

 it equals Lea's Anodonta hlaiiiviUcana. In the X'oyage Amer- 

 ique Meridionale he describes this species, stating that the anal 

 end is rounded, a character quite different from that of Lea's 

 species, but exactly like that of the Leih palvinata of Hupe. 

 I have not had access to Charpentier and Jan's catalogue, nor 

 am I aware that the latter described Anodonta esula prior to 

 1835. It would probably be better to use Hupe's name, as he 

 gave good figures and a description of his species. 



Leila Spixii (von Ihering). 



Shell irregularly obovate, thin, inflated, concentrically stri- 

 ate, somewhat inequilateral; beaks full; hinge line straight; 

 anterior end narrowed, angled above, rounded below; base 

 slightly cut away in front, rounded for the most part, quite 

 full at the middle ; posterior end subtruncate above, rounded 

 below ; epidermis pale olive-green, with dark brown bands and 

 faint, dark green rays ; muscle scars large ; nacre bluish-white, 

 iridescent ; pallial line irregular, distant from the border, hav- 

 ing an irregular posterior sinus. 



Length 84. height 59 mm. 



Amazon River. 

 Anodon giganteiis Sptx (part), Test. Bras., 1827, p. 27, pi. 



XIX, fig. I (young). 

 Anodonta gigantea Kusti;r, Conch. Cab. Ano., 1853, p. 6, pi. 



I, fig. 2 (young). 

 Columha spixii vox Thlrinc, Arch, fiir Xat., 1890, p. 135, pi. 



IX, fig. 4. 

 Leila spixii Simpson, Syn.. 1900, p. 916. 



Von Ihering has shown in the Archiv fur Naturgeschichte, 

 1890, p. 135, that the smaller of the two shells figured by Spix 

 as Anodon giganteiis is a distinct species which he refers to 

 Columha and to which he gives the specific name spixii. It is 

 a smaller species than the Leila esula, it is not so pointed in 

 front as is that species or L. hlainvilleana, and it is faintly 

 marked with rather wide rays. 



