THE NAUTILUS. 139 



swell of the apex ; left slope very convex, more or less compressed 

 toward the apex ; right slope nearly straight below the protrusion of 

 the apex. 



Length 3.25, width 1.75, alt. 1 mm. 



Types (No. 22502 Coll. Walker) from a small pond near Cam- 

 bridge, Mass., collected by Owen Bryant. Cotypes in collections of 

 Mr. Bryant and the Philadelphia Academy. 



This little species is easily distinguished by its narrow, elongated, 

 depressed form, very eccentric apex and the costulate anterior slope. 



ANCYLUS (FERRISSIA) HINKI.EYI, n. sp. PI. ix, figs. 11-13. 



Shell oval, slightly wider anteriorly, sides equally curved, ele- 

 vated, conic ; apex nearly central, being only slightly behind the 

 longitudinal center and very slightly deflected toward the right, 

 acute, erect, with strong radial strias ; light greenish horn color with 

 the apex bright rose color ; anterior slope slightly convex, posterior 

 slope slightly concave, lateral slopes of about the same slight con- 

 vexity ; surface smooth, lines of growth fine, but irregular, no trace 

 of ribs or radial stria?, except at the apex. Length 4.75, width 3.5, 

 alt. 2.25 mm. 



Type (256G1 Coll. Walker) from the Ohio River at Golconda, 111. 

 Cotypes in the collection of A. A. Hinkley, DuBois, 111. Also from 

 the Ohio at Elizabelhtown, 111. (Coll. Hinkley), and from Kentucky. 

 (Coll. Am. Mus. Nat. Hist.). 



Four specimens were submitted for examination by Mr. Hinkley 

 from the above localities. In two of the specimens, in which the 

 apices are not at all eroded, the truncation is oblique, the apical pit 

 opening towards the left. The right margin of the truncation is 

 high and smooth, the apical strias beginning just below the smooth 

 border of the truncation. On the left and lower margin of the pit 

 the apical strias radiate from the center. A. liinldeyi by reason of 

 its rosy apex groups, apparently, with A. elatior,jilosus and rhodacme. 

 Unfortunately the shells had been cleaned, so that at present it is 

 impossible to say whether it shares the anatomical peculiarities com- 

 mon to those forms. 1 



It differs from elatior by its smaller size, acute, erect apex and 



1 These species and probably all the pink-tipped Ancyli have a very peculiar 

 lingual dentition, quite different from any of the other Ancyli and form a group 

 of probably generic rank, a full description of which will be published shortly. 



