86 



COLUMBA. 



IX. SUBGENUS COLUMBA. 1 



OBOVATE. 



*Blainvilliana. 2 Lea. 



An. Blainvilliana. Lea. Chenu. 



HwpL Han. 

 An. trapezialis. Crouch. 

 An. Parishii? Gray. Han. 

 An. Mans. Sow. Reeve. 

 An. scriptus. Fer. Reeve. 

 Leila trapezialis. Hupe. 

 Lridina trapezialis. 1 I) 1 Orb. 



OBOVATE. 



Zet'/a Parishii. Gray. 



*esula. s Jim. 



ylnocZowto esula. Jan. 



Irid. esula. 6 D'Orb. 



Leila esula? Gray. Hupe. 



Leila Castelnaudii. Hupe. Mart. 



Leila pulvinata. Hupe. 



1 Testa aequivalvis, inaequilatera, subtriangulari. Cardo linearis edentulus. Impressio muscularis 

 pallii postica inflecta. 



2 In my description of Blainvilliana (Observations on the Genus Unio, vol. i. p. 189), I observed that 

 I was induced to believe that the animal of this shell would be found to differ from that of the genus 

 Anodonta. M. D'Orbigny, in his Synopsis of the Fresh Water Shells of South America, has in fact so 

 found it. The animal has two tubes. Nevertheless, although I then proposed, if such should be the 

 case, that it should be placed in a new genus, under the name of Columba, I continued it in the subgenus 

 Anodonta, as, with the artificial system, which is founded on the hinge, I thought it could not with 

 propriety be elsewhere classed. I then mentioned that when the family shall be arranged in a sj'stem 

 founded on the animal structure only, it evidently must be changed, and I doubted then if it should be 

 placed in the genus lridina, for, although it is likely that all the species of that genus have two tubes, 

 they do not seem to possess the inflected palleal cicatrix, which I noted in the description of Blain- 

 villiana. There being now at least two distinct species known, I have thought it best to classify the 

 genus Golumba as proposed March 15th, 1833 (Obs. vol. i. p. 190). 



3 In a letter from Dr. Gray, Nov. 1834, he states that his Parishii and my Blainvilliana are the 

 same. His paper is dated July 8th, 1834; mine, March 15th, 1833. 



4 M. D'Orbigny, at p. 43, Synopsis Ter. and Finn. Mollusque, makes An. trapezialis, Lam., a synonym 

 to his lridina trapezialis ; but I think that Lamarck's An. trapezialis is a different shell. I cannot but 

 think that D'Orbigny's I. trapezialis is my An. Blainvilliana. 



6 M. D'Orbigny thinks that this is my Blainvilliana, but, having his specimens and mine of both 

 these species, I am induced still to believe that I am correct. The two specimens resemble each other, 

 but are certainly distinct. The inflected palleal cicatrix exists in both, but the esula is more curved, and 

 the dorsal margin is more sinuous, the nacre being bluish white, while the five or six specimens of Blain- 

 villiana which I have seen are all salmon color. 



6 Mag. de Zooh, 1835. 



' Gray's Genera. 



