1856.] 65 



with distinct lines of growth, crossed by rounded, thread-like lines, generally- 

 less than the spaces between, and somewhat irregular in size ; between the 

 latter there are also very fine parallel revolving strife, only visiblo under a 

 lens , suture apparently canaliculate ; aperture broad ovate or oval ; outer 

 lip thin ; inner lip straight above, and distinctly curved outwards below at 

 its junction with the outer lip near the small umbilicus. Length .84 inch, 

 breadth .68 inch; apical angle regular, divergence 78; length of aperture .50 

 inch, breadth of do. .36 inch. 



Locality. Moreau trading post. No. 5 of the series. 



RosTELLARiA BiANGULATA. Shell elongated ; spire elevated, acutely conical ; 

 volutions seven or eight, convex, crossed by small nearly obsolete folds, 

 last one having two distinct revolving carin* on the middle, which diverge 

 in passing upon the expanded lip, and terminate in two more or less saliant 

 angles at its outer margin ; surface marked by fine very faint lines of growth, 

 crossed by small revolving thread-like lines about equal the intermediate 

 spaces, on the spire and upper part of the last turn, but more distinct and alter- 

 nating with smaller ones on the lower part of the body volution ; suture linear, 

 sharply impressed ; aperture unknown ; outer lip thin, expanded, and extending 

 more or less up the spire. Length .53 inch, breadth exclusive of the lip .21 

 inch ; apical angle regular, divergence 3'7. 



Locality and position. Yellow Stone river, one hundred and fifty miles from 

 mouth. No. 4 of the series. 



Fuscrs Dakotaexsis. Shell fusiform ; spire conical, somewhat elevated ; volu- 

 tions about si.x, flattened or concave above, last one abruptly contracted into 

 the canal below, and ornamented on the middle by two elevated revolving nodose 

 carinoe, between which faint, broadly rounded, vertical folds pass from node to 

 node. On the spire only the upper and most prominent carina is seen, while 

 a third less distinct parallel ridge passes round lower down on the body whorl ; 

 whole surface marked by fine, regular Hues of growth, crossed by rounded re- 

 volving lines, one of which, about midway between the two large carint^, is 

 stronger than the others ; suture linear ; aperture broad oval or ovate. Length 

 from junction of canal and aperture to apex 1.03 inches, breadth .92 inch ; length 

 of aperture .48 inch, breadth .42 inch; apical angle regular, divergence 51. 



Locacity and position. Moreau trading post. No. 5 of the series. 



Fusus Galpinianus. Shell small, fusiform ; spire conical, acute ; volutions 

 five and a half to six, convex, last one sloping somewhat abruptly below into 

 the short canal ; surface marked by fine flexuous lines of growth, crossed by 

 rounded little revolving bands or lines scarcely larger than the grooves be- 

 tween. About fourteen of these bands may be counted on the second volution; 

 suture distinct; aperture narrow-oval, acutely angular behind, and sloping 

 into the canal in front ; outer lip thin and sharp ; inner lip lying close upon the 

 tortuous columella. Length 1.05 inches, breadth .42 inch; length of aperture 

 (including canal) .53 inch, breadth .18 inch ; apical angle regular or slightly 

 convex, divergence 32. 



The above species is dedicated to Mr. C. E. Galpin, of Am. Fur Go. 



Locality and position. Same as last. 



Fusus coNTORTDS. Shell obliquely fusiform ; spire elevated conical, acute at 

 the apex; volutions five and a half to six, distinctly concave above, convex below, 

 and ornamented by indistinct flexuous folds, which swell out into a row of 

 prominent nodes round the middle ; last volution graduall}'- contracting below 

 into a short canal ; surface marked by fine flexuous lines of growth crossed by 

 numerous elevated thread-like revolving lines, a little less than the spaces be- 

 tween ; suture distinct ; aperture ovate, widest above the middle, angular behind, 

 and tapering forward ; outer lip thin ; inner lip closely folded upon the some- 

 what tortuous columella. Length about .90 inch, breadth .48 inch ; length of 

 aperture and canal .56 inch, breadth .20 inch ; apical angle convex, divergence 45. 



Locality. Same as the preceding. 



