PLEUROCERA. 



65 



9. P. fllum, Lea. 



Mdania filum, Lea, Pliilos. Pioc, iv, p. KJo. Philos. Trans., x, p. C2, t. 9, f. 41. 



Obs., iv,p.G2. BixsEV, Check List, No. 109. Buot, List, p. 30. Reeve, Mouog. 



Mel., sp. 402 ? 

 EUmia Jilum, Leu, Chenu, Man. Conchj'l., i, f. 1980. Adams, Genera, i, p. 300. 



Description. — Shell carinate, conical, rather thin, dark horn-color; 

 spire elevated ; sutures impressed ; whorls flattened, carinate in the 



Fig. lii4. 



Fig. 12."). 



Fig. 125a, 



Fig. 12G. 



Fig. 127. 



middle; aperture small, rhomboidal, angular at the base, within 

 "vvhitlsh, columella twisted. 



Habitat. — Alabama. 



Diameter, -47; length, 1-00 inches. 



Observations. — A single specimen only of this species was sub- 

 mitted to me by Major LeConte. It is very nearly allied to M. elevata, 

 Say, but may be distinguished by its thread-like carina on the middle 

 of the whorls, which, on the superior ones, presents a mere simple 

 line. The outer lip is remarkably patulous, presenting the auger- 

 shaped lip which belongs to a certain group of the Mclanice. The 

 apex being imperfect, the number of whorls cannot be ascertained. 

 There are eight visible on this specimen, and it probably possesses 

 ten in a perfect state. The aperture is about one-third the length of 

 the shell. — Lea. 



This species has by many been considered a variety of 

 canalicidatum ; my impression is, that it is well distinguished 

 by its more strictly conical shape, ilattened whorls, And more 

 elevated carina on the periphery. It almost entirely replaces 

 canalicidatum in the waters of Tennessee (I have seen numer- 

 ous specimens from all portions of the state), and, if specifically 

 identical with the latter species, must at least be distinguished 

 as a local variety. The type figure which I have copied (fig. 



I,. F. W. S. IV. 5 



