156 PROCEEDINGS OF THE ACADEMY OF [March, 



b^. — Spiral strise well developed, subequal; last whorl not deflexed 

 at aperture. 



c. — Umbilicus very wide; last whorl narrow, aperture very- 

 small. Arizona and New Mexico, 



H. e. arizonensis n. subsp. 

 c^^Umbilicus smaller, more cup-shaped, last whorl wider. 



Texas, H. eigenmanni Pils. 



6^. — Spi'-als coarse, some of them more conspicuous, with a cutic- 

 ular fringe ; last whorl in full}^ adult shells abruptly deflexed 

 in front. East Tennessee, North Georgia, //. fimhriatus Weth. 



Helioodisous parallelus (Say). PI. VIII, figs. 7. 8, 9, 10. 



Helix lineata Say, Journ. Acad. Nat. Sci. Phila., I, p. 18 (1817) ; II, p. 373. 



Not Helix lineata Olivi, Zool. Adriatico, p. 177 (1792). 

 Planorbis araUeUuf< Say, Journ. A. N. S. Phila., II, p. 164, (1821), corrected 



to paraUellus in the Index, p. 407. (Upper Missouri.) 

 Helicodisciis lineatus Morse, Journ. Portland Soc, I, p. 25, figs. 61, 62, pi. 



2, fig. 3; pi. 7, fig. 63 (1864). Binney, Man. Amer. Land Shells, p. 75. 



This common species has been well described by Binney and others. 

 It has ordinarily four whorls, but there may be as many as 4J in excep- 

 tionally large shells. At least one pair of tubercular teeth may be 

 seen in most specimens. Shells of maximum size measure: 



Alt. 1.3, diam. 3.5 mm. (Grand Rapids, Mich.) 



Alt. 1.25, diam. 8 mm. (Philadelphia.) 



The typical form of H. 'parallelus is before me from localities in 

 Ontario, Maine, Massachusetts, Connecticut, New York, New Jersey, 

 Pennsylvania, Maryland, District of Columbia, Virginia, North Carolina, 

 Ohio, Michigan, Minnesota, Indiana, Iowa, Kentucky, Tennessee, 

 Alabama, Florida, Missouri, Kansas, Arkansas, Indian Territory. 



I have not seen Texan specimens of typical lineatus, but it doubtless 

 occurs in northern and eastern parts of the State. 



In New Mexico, at Pecos, Las Vegas, Mesilla, Sandia mountains and 

 other places, and in the Pecos river canyon near its mouth, Val Verde 

 county, Texas, there is a form of H. parallelus with rather weak, 

 sparse spirals, the intervals more distinctly striate radially than in typical 

 parallelus. This seems to be a form of the southeastern Rocky moun- 

 tains and southward to the Rio Grande, occupying territory between 

 the ranges of H. eigenmanni and H. arizonensis, with some overlapping 

 on the territory of the latter. 



Say's first name. Helix lineata, was preoccupied, but his Planorbis 

 parallelus applies to the same species. In the text of the Journal the 

 first letter of the name did not print up, but the space in place of it 

 shows that it had been there, and the p is correctly supplied in the 

 index. The type used in that volume of the Journal was old and full 



