On Propkysaon, etc. 307 



In W. G. Binney's Synopsis (Smith. Inst. Coll., p. 4, 

 Dec, 1863) Htjalina (Conulus) mmuiissima, Lea, is enu- 

 merated, and Tryon (Amer. Jour. Conch., II, p. 257, 1866) 

 placed the species in Conulus, while quoting the particulars 

 given by Morse,. of the jaw. 



In 1868, Lindstroni (Gotlands Nut. Moll., taf. iii, f. 12) 

 published figures, but without description, of the jaw of 

 II. pygmoRa. On comparison of this with Morse's figure of 

 minutissima , the identity of the two species could scarcely 

 be inferred. 



In our Land and Fresh- water Shells (Part I, p. 221, 1869) 

 we adopt Punctum, Morse, as the generic name of Lea's 

 species, treating that genus as belonging to Orthalicince, by 

 reason of the structure of the jaw. 



W. G. Binney (Invert. Mass. 2d ed., p. 403, fig. 665, 

 1870) has Hyalina minutissima as occurring in Massachusetts, 

 adding in a note "the character of the jaw would place the 

 species in the subfamily Orthalicince, as a distinct genus for 

 which Morse's name Punctum might be retained, otherwise 

 the species would be placed in Hyalina." 



Mr. J. Gwyn Jeflreys (Ann. & Mag. Nat. Hist., Oct., 

 1872) refers to Hyalina minutissima as being identical with 

 Helix pygmoia, Drap. 



Dr. G. Schacko (Malak. Blatt., p. 178, 1872) has re- 

 cently described both jaw and lingual teeth of II. pygmoia, 

 showing that both have the same characters as ascribed by 

 Morse to Punctum minutissimum. 



The foUovvilig is a translation of Schacko's description of 

 the jaw of H. pygmma: — 



"The jaw consists of nineteen plates, which are grouped in the form 

 of a horse-shoe. They lie together like the tiles of a roof, and partially 

 cover one another. The plates are connected by a fine transparent mem- 

 brane. The middle plate, which is the largest, and perfectly straight at 

 the top, lies entirely alone, so that a space is visible between it and the 

 two next side-plates. These are smaller and of the same length, while 

 the top is slightly curved. The plates have the same form as regards 

 their length, but the curve increases towards the end plates. The third 



