1895. 



FROCEEDINGS OF THE NATIONAL MUSEUM. 29 



inner lip aud descending, with a twist, ui)on the apical region of the 

 concealed spire ; the shell is sharply constricted just in front of the apex, 

 and the vortex thus included is swollen and strongly transversely 

 wrinkled; surface of the shell polished, spirally grooved toward each 

 end, smooth toward the i^eriphery; aperture rather narrow, somewhat 

 anguhited at both apices; pillar straight, reflected, with a narrow 

 groove behind it; outer lip thin, simple. Longitude, 4.5: maximum 

 diameter, 2.5 mm. 



Jf(//>/7af.— Chipola beds (2213), Chipola Eiver, Florida. 



Tijpes.—^o. 113889, U. S. X.M., and in the collection of Mr. Aldrich. 



It is iirobable that all the specimens which have served for this de- 

 scription are immature, but it is quite certain they are not the young 

 of any species of Aixjs now known from our Tertiary. 



ATYS (ACROSTEMMA) GRACILIS, new species. 



Shell small, slender, with the aperture longer than the body, which 

 is obscurely enlarged about the middle, slopes biconically from this 

 girdle above to the apex and below to the region just behind the upper 

 end of the pillar, from whence it is more rapidly attenuated to the ante- 

 rior end of the shell; spire sunken, the i)it varying in size in different 

 specimens, the margin slightly thickened and transversely striated; 

 middle of the whorl smootli, but the distal portions more or less dis- 

 tinctly spirally grooved; the lines of growth are feeble; apertm^e nar- 

 row, espe(;ially behind, where it is a good deal produced above the apex, 

 with its inner lip slightly twisted; in front the pillar is twisted and 

 fiiintly grooved, with a shallow chink behind it; in front it is obscurely 

 obliquely truncate where it joins the anterior curve of the outer lip. 

 Longitude 5; maximum diameter, 2 mm. 



HahHat.—Q\i\\^o\ii beds (2211, 2213). 



Types. -^o. 113892, U. S. N. M., and in the collection of Mr. Aldrich. 



M. Cossmann notes that this section forms a passage, as it were, from 

 CyUchna to Atys^ but it would seem to the writer that it is more 

 nearly related to the latter, and should rank as a section of Atys rather 

 than of CyUchna. 



ATYS (ACROSTEMMA SALINA, new species. 



Shell small, rather slender, involved, with a polished surface, and the 

 aperture produced in a point behind the spire; body of the shell wider 

 anteriorly; sculpture of fine incised lines, closer and more numerous 

 anteriorly, becoming sparse about the middle of the shell, and nearly 

 absent toward the spire, except at the extreme end; surface other- 

 wise smooth, except at the posterior end, where close-set, straight, 

 sharp, rather deep axially directed grooves extend from the apex for- 

 Avard about one-fifth the length of the shell; aperture narrowest in 

 the middle; outer \\\) axially straight, incrementally somewhat arched, 

 behind produced beyond the spire to a rather narrow point, whence it 

 returns with a twist on the body, covering the apical region with a rather 



