UNIVERSALLY DISTRIBUTKD SPECIES. 71 



epidermis is the same iu both. The luster of the epidermis resembles 

 that of satin. 



It has been suggested that striatella is identical with H. omphalos, 

 Searles Wood, an Eocene fossil of Headon Hill, Isle of Wight. 



OTEICROPIIYSA. (See below.) 

 Mici'ophysa pyg:nisea, Drap. 

 Shell umbilicated, subglobose, reddish horn-color, ^ig. 31. 



shining, marked with strong transverse strife and micro- 

 scopic revolving lines, both most prominent near the um- 

 bilicus ; whorls 4, convex, gradually increasing, the last 

 broadly umbilicated; aperture subcircular, oblique; 

 peristome simjile, acute, its columellar extremity subre- 

 flected. Greater diam.eter, l^'"™ ; height, 1'^^°'. 



Helix pygviwa, Drap., &c. 



Helix viinutissima, Lea, Trans. Am. Phil. Soc, ix, 17; Proc, ii, 82 (1841); Obs., iv, 17 



(1848).— Troschel, Arch. f. Nat., 1843, ii, 124.— Pfeiffer, Mod. Hel. Viv., i, 



87. — W. G. BiNNEY, Terr. Moll., iv, 100, pi. Ixxvii, figs. 6, 7.— Morse, Am. 



Nat., i, 546, fig. 46 (1867). 

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

 Punctum minutissiinum, Morse, Jouru. Portl. Soc, i, 27, figs. 69, 70, pi. viii, fig. 71 



(1864).— AV. G. Bixney, L. & Fr.-W. Sb., i, 222 (1869); T. M , v., 411. 

 Conulus minutissima, Tryon, Am. Journ. Concb., ii, 257 (1866). 

 Hyalina minutissima, Gould and Binney, Iuv. of Mass. (2), 403 (1870). 



Maine, Massachusetts, New York, Ohio, Bosque County, Texas, in the 

 Eastern Province; San Francisco, Lone Mountain, California, iu Pa- 

 cific Province. Probably will be found over all the continent. In North- 

 ern and Central Europe it has also an extensive range. 



I repeat below the complete history of the species as given bj' Bland 

 (Ann. Lye. Nat. Hist, of N. Y., X. 306). 



This species was described as Helix minutissima by Dr. Lea iu 1841. 

 In 1864 Professor Morse thus described its jaw : "The buccal plate is 

 made up of sixteen long, slender, corneous laminae, recurved at their 

 cutting edges, these plates partially lapping over each other," 



Morse remarked on the similarity between Lea's species and H. pi/g- 

 mcea, Drap., of Europe, adding, "And it seems singular that it has never 

 been referred to that species"; but after examination of the jaw of the 

 latter, as figured by Moquin-Tandon, Morse considered it generically 

 distinct. He suggested the name Punctum. 



The following is Moquin-Tandon's description of the jaw of H.pygmwa 

 (Moll, de France, II, p. 103, Plate X, Fig. 2, 1855) : 



