6 PROCEEDINGS OP THE NATIONAL. MUSEUM vol.71 



XENOHELIX, new genus 



XENOHELIX MARYLANDICA, new species 



Plate 2, figs. 1-4 



The specimen selected as the holotype is not entire, consistin<!; of 

 four remaining whorls. The diameter of the smaller end of the 

 spire is more regularly and symmetrically coiled than the larger end, 

 which suggests an irregularity in the habit of coiling. The surface 

 is roughened by rounded or elongate elevations. The peripheral wall 

 is thin, whereas the core is much thicker and constitutes the greater 

 part of the tube. The character of the peripheral wall and core are 

 as given under the description of coiled forms on page 3. 



The measurements of the holotype in centimeters are : Length, 

 20.3; maximum diameter of larger end, 5, core of same end, 4; 

 maximum diameter of smaller end, 3, core of same end, 2.1. Cat. 

 No. 354137, U.S.N.M. 



Type locality: Station 1/1049, low bluff on west shore of Chesa- 

 peake Bay, about 6i/^ miles south of Cedar Point and one-third 

 mile above the site of the old Langley homestead, St. Marys County, 

 Md, Bed No. 1 of section No. 2, page 2. L. W. Stephenson, collector. 



The following bibliography of Daimonelix and other coiled forms 

 has been prepared. Although this may be irrelevant to the subject 

 of this paper, it will, however, serve as a reference to the literature 

 on these very interesting forms referred to Daimonelix. 



BIBLIOGRAPHY OF DAIMONELIX 



Abex, O. Grundziige der Palaeobiologie der Wirbeltiere, pp. 84-86, 1 fig., 



1912. 

 Barbour, Erwin Hinckley. Notice of new gigantic fossils : Science, vol. 19, 



pp. 99-100, 3 figs., 1892. 



Notes on a new order of gigantic fossils: Nebr. Univ. Studies, vol. 1, 



pp. 301-335, 18 figs., 6 pis., 1892. 



Abstract, Journ. Geology, vol. 1, p. 421, 1893. 



Additional notes on the new fossil, Daimoneliw. Its mode of occur- 

 rence, its gross and minnte structure : Nebr. Univ. Studies, vol. 2, 

 pp. 1-10, 1 fig., 12 pis., 1894. 



Is Daemonelix a burrow? A reply to Dr. Theodor Fuchs : Amer. 



Naturalist, vol. 29, pp. 517-527, 3 figs., 1 pi., 1895. 



History of the discovery and report of progress in the study of 



Daemonelix: Nebr. Univ. Studies, vol. 2, pp. 81-124, 20 figs. 18 pis., 

 1897. (Read before the Nebr. Acad. Sci., Jan. 3, 1896.) 



Progress made in the study of Daemonelix [Abstract] : Nebr. Acad. 



Sci. Proc. for 1894-1895, Pub. 5, pp. 24-28, 18 figs. (1896). 



Nebr. State Board Agr. Ann. Rept. for the year 1896, pp. 338-342. 



18 figs. (1897). 



Nature, structure, and phylogeny of Daemonelix: Geol. Soc. Amer. 



Bull., vol. 8, pp. 305-314, 9 pis., 1897. (Read before the Society, Dec. 

 31, 1896.) 



Abstract : Journ. Geology, vol. 5, pp. 223-224, 1897. 



Abstract : Science, n. s., vol. 5, pp. 91-95, 1897. 



