220 



1. E. semenoides, Gabb, Joum. Ac. Nat. Sc. Phil. 2d ser. iv, 



888, pi. 67, f. 49, Mch. 1860. Eocene; Texas. 



2. E. subcypraeola, Orb. 



Marginella ciiprcvola, Basterot (not Brocchi), Mem. Geol. p. 



"44. 1825. Michelotti, Foss. Terr. Mioc. del'It. Sept. p. 



321, 1847. 

 Erato suhcyprceola, Orb., Prodromus, ii, 31, 1852. 



Miocene ; Piedmont. 



E. VEXTRTCOSA, Gray (Desc. Cat. p. 17, 1832), has not been 

 recognized. 



Genus MARGINELLA, Lamarck. 



Oueumis (in part), Klein, Tentamen, 1753. 



PorceUana* (in part), Adanson, Voyage de Senegal, p. 55, 1757. 

 Peribolus (in part), Adanson, Voyage de Senegal, p. 75, 1757. 

 Voluta (in part), Linn., Syst. Nat. ed. x, 729, 1758. 

 Marginella^ Lam., Prodromus, 1799. Syst. Anim., p. 75,1801. 



Ann. du Mus. ii, 60, 1802. . 

 Yolvaria (in part), Lam., Syst. Anim. sans Vert, vii, 362, 1822. 



Including subgenera of authors, viz. : 

 Persicula, Schum., Nouv. Syst. p. 235 (type M. persicula, L.), 



1817. 

 Hyalina, Schum., Nouv. Syst. p. 234 (type 31. jyalUda, Don.), 



1817. 



* The name Porcellann was first applied to the Cowries by Rumphius 

 in 1705, was set aside by Liniiifus in favor of Cyprcea in 1740, was taken 

 up by Adanson in 1757 for the present genus (which he was the first to 

 well define), and was judiciously dropped by Lamarck in 1799. Its ety- 

 mology is barbarous and indecorous, and its restoration for either Cyprcea 

 or Margmella is hardly called for by any accepted law, and can only pro- 

 mote confusion. 



As to the numerous subgenera which have been proposed for species of 

 this genus, they seem to me to be neither useful nor well grounded. In 

 a series of two or three hundred species it is easy to select a few salient 

 forms for subgeneric types, but much less easy to allot all the intermedi- 

 ate species to their proper places under such types. All the proposed 

 subgenera are founded on the greater or less prominence of the spire, 

 and on the degree of the thickening or reflection of the outer lip. A very 

 slight difference of the plane of development is all that is involved in the 

 former character, and all students of the great family Helicidce under- 

 stand well how little generic value attaches to either character. An evi- 

 dence of the invalidity of these distinctions is furnished in the inconsis- 

 tencies of the catalogues in which they have been employed. The lingual 

 dentition, when fully studied in a sufficient number of species, may yet 

 guide us to proper groups ; but even of this I am less hopeful than for- 

 nierlv. 



