Lingual Dentition of Pineria Yiequensis^ Pfeiffer. 25 



them ; inner cusp simple and pointed, instead of semi-circular,, 

 as in the preceding groups. 



This group includes L. Maugeri, Wood, zehrina^ Blandiana, 

 mad'ostoma^ Paivana, Jlexuosa, Gossei, and tricolo7\ all of Ja- 

 maica, and Z. virginea of Hayti. 



5. Gkoup E. Macroceeamus, Guilding. 



Lateral teeth very numerous, as in the preceding group ; 

 marginal teeth of the same type also ; two inner cusps. 



This includes forty-eight species, of which only four are 

 found on the continent of America; the balance belong to the 

 Antilles, particularly to Cuba, which alone has thirty -four. 



The other species formerly referred to the genus Cylindrella^ 

 are placed by Crosse and Fischer in the genera Eucalodium, 

 Berendtia and Holospira^ of the family Ilelicidce ; their lin- 

 gual membranes resembling those prevailing in that famil}^ 

 The limits of the present paper preclude our entering further 

 on this part of the subject. 



The authors remark that the three above-named genera of 

 Ilelicidce, are localized in a relatively small portion of the 

 American continent (Texas, Lower California, Mexico, and 

 Guatemala), where there are very few representatives of Cylin- 

 drella proper, while the family Cylindi^ellid m is largely de- 

 veloped in the Antilles (Cuba, Jamaica, and Hayti especially), 

 with an entire absence of the Cylindrelliform genera belonging 

 to Ilelicidm. 



From the subjoined descriptions of the jaw and lingual denti- 

 tion of Pinericb Viequensis, it will be seen that it belongs to the 

 family OylindrellidcB as restricted hj Crosse and Fischer. If 

 form of shell be considered, the species may be placed in the 

 above-mentioned group E {Macroceramus), but from the cliar- 

 acter of tlie dentition it is rather a member of group A {Cylin- 

 drella). The resemblance of the dentition of P. Viequensis to 

 that of Cyllndrella Trinitaria, Pf. {Amer. Jour, of Conch.^ iv., 

 187) is very striking. 



