372 PROCEEDINGS OF THE ACADEMY OF [1880. 



spire, or slightlj- exceeding it, tlie canal gently curved, moderately 

 contracted, and somewhat expanding at the extremity ; outer lip 

 thin, and showing internally the external ornamentation ; base with 

 numerous revolving lines, which alternate in coarseness. 



Length, 1^ inch. Kniglit's Branch ; Cave Branch, Clarke Co., 

 Alabama. 



Fusus interstriatus, n. sp. PI. 20, fig. 11. 



Shell fusiform, slender, composed of about ten convex volutions, 

 the first three of which are smooth ; whorls ornamented with both 

 longitudinal plications and revolving lines, the last of which (about 

 eight in the upper whorls) alternate with finer intermediate stride ; 

 the longitudinal plications distinct on the earlier whorls, but 

 becoming much less so on the body-whorl, and the one preceding ; 

 aperture about the length of spire ; the canal somewhat tortuous ; 

 outer lip thin, dentate within. 



Length, 2 inches. Knight's Branch ; Cave 'Branch, Clarke Co., 

 Alabama. 



Subgenus HEMIFUSUS? 



Fusus (Hemifusus T) engonatus, n. sp. PI. 20, lig. 8. 



Shell turreted, of about ten volutions, the first three whorls 

 smooth and convex, the remainder strongly carinated, and tra- 

 versed by numerous fine revolving lines, which on the median 

 portion of the body -whorl alternate with intermediate finer stride ; 

 body-whorl impressed immediately below the carination (shoulder 

 angulation) ; lines of growth sinuous, and approximating the 

 characteristic lines of the Pleurotomidae ; aperture considerably 

 exceeding the spire in length; columella slightly arcuate, and 

 presenting a rudimentary fold at a))out its central portion. 



Length, 1^ inch. Wood's Bluff; Clarke Co., Ala. 



This species resembles the Fusus bifascialus of Deshayes 

 {Animaux sans Vertebres, Bassin de Paris, II, pi. 84, figs. 15 and 

 16) from the Paris basin, but may be readily distinguished from 

 that species by its more slender form. 



Subgenus STREPSIDURA, Swaiuson. 

 Fusus (Strepsidura) subscalarinus, n. sp. Pi. 20, fig. 7. 



Shell somewhat bucciniform, whorls about eight, sub-angular, 

 the first three or four smooth, the remainder ornamented with 

 both longitudinal costae and revolving striae, the latter showing a 



