MEL ANT no. 



4T 



tion proves to bo sufficiently distinct to form a new species. On account 

 of its color I call it 



Paludina cornea. — Shell ovate-conic, thin, opaque, greenish horu color; 

 whirls 5, subrounded ; sutures deeply impressed. 



This species has an obtuse apex ; the last whirl is one-third longer than 

 the others ; each of them has a kind of flattening (aplatissiment) which 

 forms a balustrade (rampe) around the spire, whose sutures are deeply 

 impressed. The striae of growth are vertical and fine. The aperture is oval. 

 Horn colored,with a greenish tinge ; the interior of the mouth and lip is white. 



The largest individual was 11 lines in length. {Valenciennes.) 



Figure 93 represents a deformed specimen of Melantho decisa, 

 from the Susquehanna. It is introduced 

 here for the purpose of showing how ab- 

 normal an individual of a species may be. 



Another abnormal form of Melantho de- 

 cisa, in which the whirls are more numerous 

 and tapering, which is often met with in 

 any large number of specimens, has been 

 described as a distinct species as Paludina 

 milesii. The original description is given 

 below, as well as a figure of one of the origi- 

 nal specimens, presented by Prof Miles. Melantho decim, deformed. 



Fig. 94. Paludina milesii. — Shell smooth, subpyramidal, sub- 



solid, imperforate ; spire lengthened ; sutures deeply 

 impressed; whirls 6, subinflated ; aperture somewhat 

 small, subovate ; labrum acute, somewhat sinuose ; 

 columella somewhat thickened both above and below. 

 Branch Lake, Antrim Co., Michigan. M. Miles. {Lea.) 



No. 8921-4 of the collection Fig. 95. 



were presented by Dr. James 



Lewis under the unpublished 



name of Paludina obesa, Lewis. 

 Fig. 95 represents one of them. This form is a 

 well marked variety, found near Mohawk, N. Y., 

 in Ohio, and Michigan. It is readily distin- 

 guished by its very ventricose, rounded form and 

 dark olive green color. Its name is preoccupied. paiudina obesa. 



It is customary, in collections, to separate the 

 more elongated forms of Melantho decisa under the name of JI 

 Integra. It becomes necessary, therefore, to ascertain what shell 

 Mr. Say had before him in drawing up the description of Palu- 



Paludina milesii. 



