HYALINA. 403 



&c., and also in moist beds of leaves in forests. It is not rare in 

 Vermont, and Mr. Say orig-inally found it in Georgia. Common to 

 the boreal regions of the three continents. It appears to inliabit all 

 of Eastern North America, having Iwen found from Great Slave 

 Lake to Texas and Florida. Dr. Newcomb catalogues it among the 

 species found at Lake Tahoe, California. 



This is a very well-marked shell, not lial)le to be confounded with 

 any other species except H. labijrintldca^ which is of about the same 

 size and shape. But the coarsely wrinkled surface of the one, and 

 the polished, highly reflecting surface of the other, are distinctions 

 whicli strike the eye at once; if anytliing further is needed, the par- 

 allel ridges within the mouth of H. labijrinthica will put the ques- 

 tion beyond a doubt. When viewed from above, its numerous, nar- 

 row, accurately adjusted volutions render it a very beautiful object. 



Hyalina minutissima. 



Shell Rub-globoso, reddish horn color, shining; whorls four, convex; aj^erture 

 sub-circular; peristome simple; umbilicated. 



Helix minutissima, Lea, Tr. Am. Phil. Soc. ix. 17 ; Proc. ii. 82 (1841) ; Ohs. iv. 17 (1844). 



— Troschel, Ar. f. Nat. 184.3, 124. — Pfeiffer, Mon. Ilel. Viv. i. 87. — W. G. 



BiNNEY, Terr. Mull. iv. 100, pi. 77, figs. 6, 7. — Morse, Am. Nat. i. 546, fig. 45 



(1867). 

 Helix minuscula, teste Binney, Terr. Moll. ii. 221. 



Punctum miiuitissimum, Morse, Joiirn. Portl. Soc. i. 27, figs. 60, 70; pi. 8, fig. 71 (1864). 

 Conuliis minutissima, Tryon, Am. Journ. Conch, ii. 257, pi. 4, fig. 63 (1866). 



Shell umbilicated, sub-globose, reddish horn color, shining 

 marked Avith strong transverse stride and microscopic 

 revolving lines, both most prominent near the umliili- 

 cus ; whorls four, convex, gradually increasing, the 

 last broadly umbilicated ; aperture sub-circular, ob- 

 lique ; peristome simple, acute, its columellar extrem- 

 ity sul (-reflected. Greater diameter one and a half mill. ; height, 

 one millimetre. 



Maine, Massachusetts, New York, Ohio. 



Jaw * composed of sixteen long, slender corneous lamiufe, re- 

 curved at their cutting edges, these plates partially lapping over 

 each other. 



Lingual membrane with fifty-one arched rows of lo - 1 - 13 



* The character of the jaw would place the species in the sub-family Ortluilicincp., as a 

 distinct genus, for which Mr. Morse's name Punctum might be retained, otherwise the 

 species would be placed in Ilijalina. 



05 



