OF CONCHOLOGY. 129 



Nerita siqnata, Lam. 



1838. An. sans Vert., vol. 8, p. 610. 



1847. Nerita musiva, Gld., Proc. Bost. Soc, p. 238. 



1852. " " " Am. Ex. Ex., p. 165, fig. 197. 



Neritina Nuttallii, Reel. 



1841. Rev. Zool. Soc. Cuv. p. 146. 



1843. N Sandwichensis, Phil, non Desh., Neu. Con. p. 29, pi. 

 1, fig. 14. 



" N lugubris, Phil., Neu. Con. p. 29, pi. 1, fig. 9. 

 1850. " solidissima, Sow., Thes. Con. p. 541, fig. 273. 



" " alata, Sow. 

 1852. " Nuttallii, Soul., Voy. Bonite, pi. 34, fig. 43, 46. 



1855. " solidissima, Rve., Con. Icon. Sp. 77. 

 " " cariosa, Rve., " " Sp. 60. 



1856. " lugubris, Rve., " " Sp. 160. 

 " " cariosa, Gray, Ind. Test. pi. 8, fig. 9. 



This species varies in shape according to age, the young being 

 but slightly dilated, as figured by Philippi under name of lugu- 

 bris, and in a more advanced stage as Sandwichensis. 



N. neglecta, Pease, is allied to the above. It differs in being 

 more compact in shape, not dilated and regularly grooved con- 

 centrically, and finely radiately striate ; also often mottled with 

 white and black, as well as spotted. The white spots on Nuttallii 

 are small and obscure ; both species are, however, found entirely 

 black. Neglecta, Pease, is a marine species ; Nuttallii, Reel., 

 lives in fresh or brackish water. 



Neritina dilatata, Brod. 



1832. Proc. Zool. Soc. London, p. 201. 



1850. N jiorida, Reel., Jour, de Con. p. 160, pi. 7, fig. 6, 7. 



The shape of this species, as in all of the genus that inhabit 

 fresh water, varies according to age. The variety described by 

 M. Recluz is common. Specimens are met with radiately striped 

 with reddish-brown, and very slightly dilated. 



Neritina reticulata, Sow. 



1832. Proc. Zool. Soc. p. 201. 



1850. N. Desmoulinsiana, Reel., Jour, de Con. p. 162. 



1856. " Desmoulinsii, Rve., Conch. Icon. Sp. 136. 



The latter is immature, without reticulations, which is of com- 

 mon occurrence at Tahiti. At the Paumotus, where it was col- 

 lected by Mr. Cuming, it attains a larger size, and more openly 

 reticulate. At both localities it is often regularly concentrically 

 grooved. 



