PALUDINA CARINATA. 27 



SYNONYMS AND REFERENCES. 



Paludina carinata, Valenciennes, in Rec. d'Obs. de 

 Zoologie, &c, par Humboldt et Bonpland, vol. ii. p. 

 252, pi. lvi. fig. 2, a, b. 



DESCRIPTION. 



Shell conoid subdiaphanous and slightly 

 umbilicated; having five convex turns which 

 are longitudinally striated, and transversely 

 carinated, with four elevated lines, of which 

 the first and third are larger than the second 

 and fourth: aperture angulated posteriorly, 

 nearly circular, but having the longitudinal 

 greater than the transverse diameter; the 

 peristome is slightly thickened, and the edge 

 is not sharp. 



Color green; with a tinge of brown upon 

 the last whirl; aperture white. 



Geographical Distribution. Mexico. 



OBSERVATIONS. 



This species was discovered by Humboldt in 

 Mexico, and is admitted on the authority of 

 Valenciennes, who wrote the concholoffical 

 part of the work cited; and from which I have 

 taken the above descriptions, and my plate of 

 the shell. 



