JVelson on Tertiary/ Ilollusca of Peru. 193 



lip produced above the top of the shell. These charactei's, together 

 \\dth the general form, lead me thus to refer the specimens, although 

 specific detei'mination is impossible. 



Myurella tuberosa, sp. nov. 



Shell turreted, slender and acuminate ; whorls eight to ten, depressed 

 or slightly concave, except the body whorl ; sutures indistinct. Cinc- 

 ture broad, elevated, with obtuse tubercles, not as wide as the spaces 

 between them. Longitudinal ribs distinct. Whorls marked by from 

 four to six nearly equal transverse ridges, which rise into strong tuber- 

 cles over the ribs. 



Body whorl large, over one-third the length of the shell, depressed 

 above, convex below, rising in the middle into more or less of a 

 shoulder. Shoulder marked by two or three concentric ridges, cov- 

 ered by tubercles much larger than those of the others. Base 

 nearly destitute of tubercles, but with the concentric lines very dis- 

 tinct. Whole surface, on well preserved specimens, marked by fine, 

 minute, longitudinal lines. Aperture elongated-oval ; ou.ter lip 

 sharp; columella jjlicated; canal well reflexed, with the keel only 

 moderately elevated. Only three specimens of this species were 

 found, all having the apex slightly broken. Seven whorls give the 

 following measurements: length 25 '2 millira. ; breadth at shoulder 

 8'4 millim, ; breadth at upper whorl 1 '95 millim. 



Myurella, sp. ind., A. 



A badly worn and broken specimen apparently represents another 

 species. Wlioi'ls convex. Cincture scarcely raised above the level of 

 the whorls, mai-ked by rather small tubercles, and separated by deeply 

 impressed sutures. Longitudinal ribs strong. Body whorl evenly 

 convex and without a shoulder, concentric lining indistinct. Four 

 whorls, giving the following measurements, show this to be a less 

 slender species than M. tuherosa Nelson. Length 2 8 "45 millim. ; 

 breadth 10 "4 millim. ; breadth at upper whorl 8 '4 millim. 



If the characters given above be constant, the specimen is quite 

 distinct from the M. tuberosa, but it has not characters suiRcient 

 for complete specific determination. 



Myurella, sp- iad., B. 



A single specimen difiers from the species described above in having 

 only slightly convex whorls and indistinct sutures. Cincture elevated 

 above the level of the whorL Longitudinal ribs strong ; transverse 

 ridges broad. Three whorls measure: length 26*2 millim.; breadth 

 98 millim. ; breadth at upper whorl 7*45 millim. 



Trans. Connecticut Acad., Vol. II. 13 July. 1870. 



