DALL: MOLLUSCA and BRACHIOrODA, 299 



TRACTOLIRA Dall. 



Tractolira Dall, Proc. U. S. Nat. Mus., 1806, 18, p. 12; Smithsonian Misc. Coll. 

 Quarterly, Feb., 1907, 48, part 3, p. 365. 



Shell slender, drawn out in its coil, fusiform, with a short canal and pervious 

 axis ; outer lip simple, not expanded or lirate ; body not callous, the axis twisted, 

 with a single strong plait at its anterior edge, the young showing five or more 

 narrow, low^, thread-like ridges behind the one above mentioned, but which become 

 obsolete in the adult. 



This singular shell appears to be a degenerate abyssal form of Volutidae, but 

 which can not be assigned to any of the genera yet established. 



Type T. sparta, Dall. 



The fossil Valuta alia Sowerby, of the South American Tertiaries, has the aspect 

 of being a precursor of T. sparta. 



Tractolira sparta Dall. 



Plate 2, figure 7. 



Tractolira sparta Dall, Proc. U. S. Nat. Mus., 1896, 18, p. 13, Smithsonian Misc. 

 Coll., 1907, 48, p. 366. 



Shell elongate, slender, with a greenish or ashy adherent epidermis (more or 

 less eroded near the apex in all the specimens), and about six whorls ; nucleus 

 apparently as in Adelomelon, large, with an apical spur ; whorls drawn out, rounded, 

 with a distinct suture, the upper whorls at first smooth, then with irregular, 

 partly obsolete, transverse wrinkles, some of which cross the wliorl, but which 

 are too irregular to call ribs; surface everywhere sculptured witii numerous, 

 even, fine, flattish spiral threads, with equal or slightly wider interspaces, and 

 with well marked but not regular lines of growth ; aperture subovate, rather wide 

 in front, the outer lip simple and hardly thickened; the throat white, a thin wash 

 of callus on the body, the pillar thin, pervious, short; ti)e canal siiort and wide, 

 with hardly any siphonal fasciole ; operculum absent. Height of shell, 60 ; of 

 last whorl, 43; of aperture, 28; diam. 19 mm. 



U. S. S. " Albatross," stations 3360, 337 1, 3414, and 3415, in 1672 to 2232 

 fathoms, mud, bottom temperatures 35°. 8 to 30°. 4 F. ; Gulf of Panama to Aca- 

 pulco, Mexico. U. S. N. Mus. 122,999. 



This is a very characteristic and singular abyssal shell. 



Fti/chatractidac. 



PTYCIIATRArTlIS Stimpson. 



Ptychatractus californicua Dall, n. sp. 



Shell small, fusiform, white, with a pale straw-colored periostracum and about 

 five whorls ; suture distinct, not appressed, whorls turgidly rouiulcd ; axial sculp- 



