INSTITUTE OF SCIENCE, PHILADELPHIA. 397 



strongly rippled or beaded, as is the posterior peripheral keel ; between them, 

 instead of numerous even, fine spirals, there are three or four larger, obscurely 

 waved primaries, while the remainder are small and fine ; on the base there 

 is a narrow, deep groove behind the pillar, outside of which are six or seven 

 strong, flattened spirals with the interspaces finely spirally grooved. The 

 base is rather flatter than in the majority of specimens of virginicum, and the 

 spire more straight-sided in its declivity. There are about six whorls, the 

 last of which is defective. The shell is about 1 1 mm. high, with proportions 

 similar to C. virginiaini. 



This shell may prove to be a distinct species, in which case it may keep 

 as specific the varietal name, but whether a species or a variety, it undoubtedly 

 forms an intermediate phase between C. virginicum and C. pliilanthropiis. 



Calliostoma grammaticum n. s. 

 Plate 18, figure 2 a. 



Older Miocene of the lower bed at Alum Bluff, Chattahoochee River, 

 and of the Chipola beds on the Chipola River, Florida, Burns. 



Shell with seven whorls, the nucleus small and smooth, the remaining 

 whorls strongly spirally sculptured ; the periphery is smooth and rounded, 

 overhanging like a broad rib the suture, which is closely appressed below it ; 

 between the suture and the peripheral rib are three to five strong, smooth 

 spirals, disposed in scalar fashion like steps up the spire, with sharp-cut inter- 

 spaces, the number increasing by intercalation, and the area they cover slightly 

 impressed; there is no finer sculpture on the spire ; the base is gently rounded, 

 flattish, smooth except for wavy incremental lines and two or three strong 

 spirals close to the umbilical region, which is bounded by a swollen rib and 

 imperforate ; pillar arched, a blunt tooth at the base; aperture ovate-quadran- 

 gular, smooth inside ; the young have the base flatter, with obscure, impressed 

 spiral lines and a single feeble thread near the periphery. Alt. and diameter 

 13.5 mm. 



This fine species, with its uniform smooth clean-cut spirals, is very dis- 

 tinctive and unlike any other in the American Tertiary. 



Calliostoma exile n. s. 



Chipola Miocene of the lower bed at Alum Bluff", Chattahoochee River, 

 Florida, Burns. 



Shell acute-conical, with more than four whorls, the apex of the specimen 

 decollated; whorls smooth except for lines of growth and two or three fine, 

 incised spiral lines just above the periphery; periphery prominent, rounded, 

 slightly overhanging the suture; base smooth or sparsely spirally striated, 

 imperforate, impressed, so that the periphery when the shell is held base 

 upward is elevated and forms a narrow, raised margin around the impressed 

 area it encloses ; aperture subquadrate, wider than high. Alt. of shell with the 

 last whorl deficient about 7.0; max. diam. 5.5 mm. 



