260 Transactions. — Zoology. 



tropical America."* Tasmania has forms very nearly allied to 

 ours. The genus is, as far as I am aware, not known in the 

 fossil state from New Zealand. 



Potamopyrgus corolla, Gould, sp. 



Mdania corolla, Gould, Proc. Bost. Soc. Nat. Hist., vol. ii. (1847), 

 p. 223. Mdania corolla, Eeeve, Conch. Sc. (Melania), fig. 366. 

 Amnicola corolla, Gould, U.S. Expl. Exp., vol. xii. (1852), 

 p. 129, pi. ix., figs. 149 a-c. Paludestrina cumingiana, P. 

 Fischer, Journ. de Conch., vol. viii. (1860), p. 208, pi. iv., 

 fig. 7. Potmnopyrgus corolla, Stimpson, Smithon. Miscell. 

 Coll. No. 201 (1865), pp. 49, 50. Hydrobia crossei, Frauen- 

 feld, Verh. Zool. Bot. Gesell. Wien, vol. xiv. (1865), p. 595. 

 (?) Hydrobia ciliata, Frauenfeld, I.e., p. 1025. Bythindla co- 

 rolla, Tenison- Woods, P.L.S. N.S.W., vol. hi. (1879). p. 135, 

 pi. xiii., figs. 2, 3, 5. Hydrobia corolla, v. Martens. Crit. 

 List N.Z. Moll. (1873), p. 14. Hydrobia corolla, Hutton, 

 Manual N.Z. Moll. (1880), p. 83. Potamopyrgus cumingiana, 

 Hutton, Trans. N.Z. Inst,, vol. xiv. (1882), p. 144, pi. i., 

 figs. A, F. Potamopyrgus cumingiana, Hedlev and Suter, 

 P.L.S. N.S.W. (2), vol. vii. (1893), p. 619. Potamopyrgus 

 cumingiana, Suter, Journ. de Conch., vol. xli. (1893), p. 222. 



Dr. Sturany, of Vienna, kindly informed me (in lit.) that 

 Frauenfeld proposed the specific name crossei solely in case the 

 name of Fischer, Paludestrina cumingiana, should be accepted, 

 as there exists a Paludestrina cumingi, d'Orb., of earlier date. 



Regarding the species Hydrobia ciliata, Gould, I am indebted 

 to Dr. W. H. Dall, of Washington, for the following (in lit.) : 

 ''Described as from Liberia with other shells from the missionary 

 Dr. Perkins, but appears very similar to Hutton's figure in 

 Trans. N.Z. Inst., vol. xiv., pi. i., fig. B 1. It seems as if some 

 mistake had occurred, and this shell should really have come 

 from New Zealand, but it is difficult to see how, as Gould was a 

 very careful man." Dr. P. Fischer no doubt admitted this 

 s)>( ries to be of African origin, for he says, " Nous connaissons 

 deux autres especes de la Nouvelle-Zelandc une des Antilles, 

 une de l'Afrique ; toutes sont caracterisee par la serie d'epines 

 qui ornent le dernier tour de spire. "f Pilsbry also, as already 

 stated, gives West Africa as the habitat of Potamopyrgus, and 

 is most likely alluding to the above species. 



Dr. W. H. Dall (in lit. 20, xi., 97) also kindly sent me the fol- 

 lowing information respecting the type of the genus : " Melania 



*Proc. Acad. N. Sci., Philadelphia, L891, \>. 327. 

 t Journ. de Conch., vol. viii. (I860), p. •_'<>!». 



