290 , NEW YORK STATE MUSEUM 



second, and third costae are clearly developed; the fourth costa 

 seems to have had a later origin as it is not detected till we reach 

 the later portions of this whorl. The intercostal spaces on the third 

 whorl are more uniform and not so deeply concave; the gradual 

 change to the greater concavity near the lower costa can be easily 

 seen in different portions of the fourth or body whorl. 



The name historicum was suggested by the well presented 

 ontogenic series in shell growth. 



Eunema epitome sp. nov. 



Plate 4, figures 6, 7 



Description. Shell small, turbinate, apical angle about 80°, length 

 10.3mm, whorls about four and one half, upper surfaces a little 

 flattened giving a distinct conical aspect to the upper portion of 

 shell. A well marked keel on periphery and three more of like 

 character between this and the suture; these four keels nearly 

 equidistant and clearly defining the broad, shallow, concave grooves 

 which lie between them. Keel next the suture and distant from 

 it about half the width of one of the grooves, finer and sharper 

 than the others, the second keel from suture strong and rounded 

 and touching the sides of the apical angle. The suture is formed 

 on the peripheral or fourth keel, and "the half groove of the body- 

 whorl is made to fit the base of the smaller groove of the whorl 

 above in such a manner as to make the suture show as a simple line 

 in the middle of a groove very similar to and but slightly deeper 

 than the others. Base of shell near termination of penultimate whorl 

 nearly flat making an angle of about 90° with upper surface ; nearer 

 the aperture the base becomes more convex and a tendency to lose 

 gradually the angle of the penultimate whorl is well marked; the 

 last third of the body whorl is lost but the changes introduced point 

 to a well rounded aperture. There are five revolving keels on base, 

 the three next the columella being the finer and closer together ; two 

 new ones with trace of a third are introduced soon after the com- 

 mencement of the last whorl and are in position still below the three 

 last mentioned. Very fine and obscure transverse striae, about seven 



