156 PROCEEDINGS OF THE ACADEMY OF [March, 
b'.—Spiral strize 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. 
TES he i Mo H. eigenmanni Pils. 
b’.—Spirals coarse, some of them more conspicuous, with a cutic- 
ular fringe; last whorl in fully adult shells abruptly deflexed 
in front. East Tennessee, North Georgia, H. fimbriatus Weth. 
Helicodisous parallelus (Say). Pl. 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 _arallellus Say, Journ. A. N.S. Phila., II, p. 164, (1821), corrected 
to parallellus in the Index, p. 407. (Upper Missouri.) 
Helicodiscus lineatus Morse, Journ. Portland Soc., I, p. 25, figs. 61, 62, pl. 
2, fig. 3; pl. 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 44 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. 3 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 7p is correctly supplied in the 
index. The type used in that volume of the Journal was old and full 
