OF CONCHOLOQY. 99 



Mr. Lovell Reeve, who has published an elaborate mono- 

 graph of the family,* in his preface assigns to the animals of 

 all the species a fringed mantle- margin. 



Prof. S. S. Haldeman was the first naturalist who detected 

 the diflfercnce between our own and the Oriental Melanians ;t 

 but he did not at that time apply the results of his examina- 

 tions to their obvious separation into two families. 



Mr. Isaac Lea in 1862 proposed a new genus of Melanians, 

 Goniohasis,X which, with other genera previously admitted, and 

 including Melania, Lam., he still continued to regard as be- 

 longing to the family Melaniidie, although in a foot-note he 

 writes, " I very much doubt if we have a single species in 

 the United States which properly belongs to this genus." 



Mr. Theodore Gill, in a recent paper on the classification of 

 our fluviatile Mollu3ca,§ assigns the following characters to 

 the family Alelaniidx: — 



" Teeth of lingual membrane, 3-1-3 ; gills concealed ; ros- 

 trum moderately produced and entire or simply notched ; 

 foot not produced beyond the head ; branchige uniserial ; lateral 

 jaws present. 



" Aperture of shell acuminate behind ; generally chan- 

 nelled at front ; size moderate. 



" The family of Melaniidie is here restricted to exclude 

 Fauntis, Montfort (= Pyrena, Lam.,) Melanatria, Bowditch, 

 Melatoma, Sw. (= Clionella? Gray), Melanopsis, Lam., Vihex^ 

 Oken, and Hemisinus, Sw. These appear to belong to a dis- 

 tinct family, equally distinguished by the projecting foot of 

 the animal and the notch of the aperture of its shell. 



" The family may be named Melanopidse. 



"■ The other genera or subgenera that have been proposed 

 scarcely appear to exist in nature. * * * * 



"The American Melaniidse form a peculiar subfamily, — 

 Geriphasinse.'''' 



Subsequently, in a foot-notej Mr. Gill mentions the reason 

 which caused him to make the above subfamily. " The 

 American Melaniidse, so far as I know, have not a fringed 

 mantle, and, consequently, belong to a different group." We 

 readily admit the propriety of separating the Melanopidse 

 from MelaniidiB, as a distinct family, and only wonder that 

 Mr. Gill did not make o. family of Geriphasinve, as the distinct- 

 ive characters of the animal so far as known to us, and of the 



* Conchologica Iconica, — Melania, Anculotus, Jo, Melatoma. 



t Amer. .Jour. Science, xli. 1, 31. 



i Proceed. Acad. Nat. Sciences, May, 1862. 



§ Systematic Arrangement of the Mollusks of the Family Viviparidae, 

 and others, inhabiting the United States.— Proc. Acad. Nat. Sci d 33' 

 Feb., 1863. '^ ' 



1 Ibid. p. 35. 



