GUPPY : MOLLUSCA OF TRINIDAD. 223 



35. Ancylus textilis Guppy. 

 *Amer. Journ. Conch.,' 1870, p. 311, pi. xvii., f. 9. 

 Crosse, 'Journ, de Conch.,' 1890, p. 51, No. 41, pi. ii., f. 5. 



Approaches A. moricajidi Orb. (Amer. Merid., p. 355.). 

 Ancylus parasitans Drouet, from Martinique, is likewise near if 

 not the same. Should these prove to be identical D'Orbigny's 

 name must take precedence ; and probably others of D'Orbigny's 

 and other South American and West Indian species may have 

 to be added to the synonymy. 



36. Gundlachia crepidulina Guppy. 



'Amer. Journ. Conch.,' 1870, pi. xvii., f. 10 — 11. 

 Crosse, 'Journ. de Conch.,' 1890, p. 51, No. 42. 



37. Planorbis terverianus Orb. 

 D'Orbigny, 'Moll. Cuba,' vol. i., p. 194, pi. xiii., f. 20. — 22. 

 Crosse, 'Journ. de Conch,,' 1890, p. 50, No. 39. 



38. Planorbis meniscus Guppy. 



Crosse, I.e., p. 51, No. 40. 



Very near to PI. haldemani Adams, Jamaica. 



39. Physa rivalis Maton and Racket. 

 Wood, ' Ind. Test.,' Bulla, 38. 

 Physa sowerhiana Orb., Moll. Cuba, vol. i., p. 190, pi. xiii., 



f II — 12. 

 Crosse, 'Journ. de Conch.,' 1890, p. 52, No. 43. 



It is not unlikely that Crosse is right in referring our shell 

 to Ph. sowerhiana ; but is that shell (from Cuba) any other than 

 a local form of Ph. rivalis ? The specimens I originally dis- 

 covered were small, as noted in my paper in ' Annals and 

 Magazine of Natural History,' 1866, but I have since found 

 much larger ones, including two of eighteen millimeters in length 

 by nine in breadth, dimensions considerably exceeding those 

 of D'Orbigny's figured example, and approaching Guadelupe 

 rather than Martinique specimens of the species. The propor- 



