VI 



incp including those shells with "aperture simple in 

 front, -without a distinct notch," =:= various genera 

 of iMelanians ; and a second subfamily, characterized 

 by a notched aperture to the shell, including Mela- 

 nojjsis, Lam. Dr. Gray, the only other recent sys- 

 tematist who has investigated the subject,* adopts a 

 family Melaniadce, including the subfamilies Iilsso- 

 aina, Melaniahia, Triphorina, Scalarina, and Lltl- 

 ojjlna, with a heterogeneous assemblage of marine 

 and Huviatile genera; the Melaniaina comprising 

 all the genera of American and exotic Melanians, 

 the, Cerithians, and the shells which I recently sepa- 

 rated under the family nam^e of Amnicolidce. 



It is strange that neither European nor American 

 conchologists who have studied this fjimily have 

 availed themselves until quite recently of the obvi- 

 ous differences, both in sliell and animal, between 

 the American and Oriental forms, for their complete 

 separation, notwithstanding the fact that Prof. Hal- 

 deman showed our Melanians to have a plain or 

 entire mantle-margin, whilst the Oriental species 

 have the mantle-margin fringed, thus allying the 

 latter more closely with the Cerithians than with 

 the so-called American Melanians. f 



Dr. Brot, a gentleman who has devoted much 

 attention to the Melanians, remarks t that the gen- 

 erally adopted classification of the family is very 

 confused and uncertain, but does not attempt to 

 pro]-)Osc a new one. 



Mr. LovcU Reeve, who has published an elaborate 

 monograph of the family,§ in his jDreface assigns to 

 the animals o^all the species a fringed mantle-margin. 



Prof S. S. Ilaldeman was the first naturalist who 

 detected the difference between our own and the 



♦List of the Genera of Recent Mollusca. — Troceed. Zool. Soc, 

 Loudon, 1847. 



t The American species are oviparous, the oriental species ovovivip- 

 arous; a more important distinction lirst pointed out by Dr. Wm. 

 Stimpson in Am. Jour. 8ci., xxxviii, July, isiU. 



X Cat. Syst. dcs Especes qui composent la Famille des Melanians. 



§ Conchologica Iconica,— J/e?«)a«, Anculotas, lo, Melatoma. 



