124 



[June, 



below, so as to form an obscure angle below the middle ; suture very distinct ; 

 surface faintly marked with fine lines of growth ; aperture ovate or sub-rhom- 

 boidal, angular above, widest near the middle, very narrowly rounded and ob- 

 scurely sinuate on the inner side below; columella somewhat less arcuate than 

 the outer side of the aperture ; lip thin and slightly refiexed at its junction with 

 the lower part of the columella. Length -16 inch ; breadth -05 inch ; length of 

 aperture -04 inch, breadth do. -03 inch ; apical angle regular, divergence 20" to 



This beautiful little Melania approaches very near in size as well as in form, 

 M. spina, a Miocene species described by M. Grataloup {Conch. Melan. 10, t. 5, 

 fig. 6 and 7,) but differs in having fewer and more convex volutions. 



Locality. Three miles below Fort Union. 



Melania Anthonyi. 



Shell very small, conical-ovate ; spire not much elevated ; volutions five to five 

 and a half, slightly convex, increasing somewhat rapidly from the apex, last one 

 rather large and obtusely angular below; surface marked witb fine, indistinct 

 lines of growth, crossed by extremely fine, nearly obsolete, revolving striae ; suture 

 well defitied; aperture ovate, angular above, widest a little telow the middle, 

 narrowly rounded and very faintly sinuate on the inner side below; lip thin, 

 elighily reflexed on the lower and inner side, but leaving open a small umbilical 

 perf )ration ; columella regularly arcuate. Length -18 inch ; breadth -10 inch ; 

 length of aperture -OG inch; breadth of do. -01 inch ; apical angle slightly convex, 

 div. rgence 41. 



Without a very careful examination with a good lens, in a favorable light, (he 

 extremely fine revolving strias on this neat little shell would be overlooked. In 

 form it is almost an exact miniature of M. Xebrascensis of this paper, but a care- 

 ful comparison with the young of that species of its own size, shows it to be quite 

 different. In addition to this, it occurs in great abundance at localities where 

 no authentic specimens of that species were met with. We have no doubt of 

 its being an adult shell. We name it after Mr. John G. Anthony, of Cincinnati, 

 Ohio, to whom we are under obligations for suggestions in regard to it and two 

 or three other species described in this paper. 



Licaliiy. Yellow stone river, thirty miles above the mouth. 



Melania mcltistriata. 



Shell small, elongate-ovate ; spire conical, somewhat elevated, acute at the 

 apex ; volutions five and a half to six, convex ; surface marked with fine indis- 

 tinct lines of growth, and exceedingly fine, closely arranged revolving striae ; 

 suture well defined ; aperture narrow-oval, or ovate, contracted, but scarcely 

 sinuous below; columella regularly curved. Length -23 inch ; breadth 12 inch ; 

 length of aperture -10 inch ; breadth of do. -06 inch ; apical angle regular, diver- 

 gence 39. 



This may be distinguished from the last by its more elevated spire, and more 

 elongated body whorl, which is never angular below. The aperture is also 

 narrower, and the columella imperforate. From the young of M. Nebr^iscensis 

 of its own size, it differs in bemg more elongated, and in having one or two more 

 whorls. The revolving striae are also more uniform, and so very fine as to be 

 only visible by the aid of a strong mHgnifier. 



Locality. Ten miles above Fort Union. 



Melania Nebbascensis. 

 Shell elongate-ovate ; spire conical, not very much elevated, acute at the apex ; 

 volutions about six, flattened convex; surface marked by fine lines of growth, 

 crossed by numerous more or les^ elevated revolving lines, some of which, on the 

 middle of the whorls, are sometimes so much larger than the others as to form 

 distinct carinas; suture strongly impressed; aperture ovte, angular above, 

 narrowly rounded and very faintly sinuous below ; outer lip prominent below the 

 middle ; columella regularly curved. Length -78 inch ; breadth -42 inch ; length 



