284 PROCEEDINGS OF THE ACADEMY OF [Sept., 



Genus FALSIFUSUS Grabau.n 

 Falsifusus mesozoicus n. sp. PL XVII, figs, il, 12. 



Description. — Shell small and fragile, fusiform in outline, spire 

 elevated and acute, pillar verj^ long, slender and straight; elevation 

 of spire much less than length of aperture and canal; angle of spire 

 increasing with age ; whorls closety appressed, five in number, whorls 

 of spire sharph' convex or subangular in cross-section, body inflated; 

 protoconch small, smooth and trochoid, coiled thrice ; sculpture of body 

 axial and spiral; axials strong, about ten in number on the body; 

 axial ribs angular and spinose on the keel of the shoulder of the body 

 but well rounded or nodulated on' the whorls of the spire; axials 

 absent on the shoulder and obsolete on the base of the body; spiral 

 sculpture elaborate and may be described in groups as follows: 

 a half-dozen subequal lirae on the shoulder, three on the sides of the 

 whorls of the spire, including the spiral which outlines the periphery; 

 twice as many on the medial portion of the body with intercalated 

 secondaries; four or five irregular and obscure spirals on the posterior 

 portion of the base, four stronger equal and equispaced lirse upon the 

 anterior portion of the base; about a dozen increasingly finer spirals 

 upon the pillar; suture impressed and undulated by the costse of the 

 preceding whorl; body abruptly constricted anteriorly into a long, 

 slender pillar; aperture harrow, ovate, produced in front into a long, 

 narrow canal with proximate, parallel margins; outer lip thin and 

 simple; inner lip excavated at the base of the body; columella smooth, 

 slightly twisted at the entrance of the anterior canal; parietal wall 

 thinly glazed. 



Dimensions. — Altitude 20.4 mm.; maximum diameter 8.2 mm. 



The slender and fragile shells of this species are well characterized 

 by the spinose terminations of the axials along the shoulder angle 

 of the body, the elaborate spiral sculpture and the slightly bent 

 slender pillar. The Msestrichtian species Fusus bicindus Kaun- 

 howen^^ from Belgium is probably a related species of this genus. 

 Kaunhowen's species has a higher spire and a much longer pillar than 

 the Tennessee species and resembles the type of the genus more 

 closely. These two species are the first Upper Cretaceous forms 

 to be referred to Grabau's genus Falsifusus. 



"Grabau, A. W., 1904, "Phylogeny of Fusus and its Allies," Smiths. Misc. 

 Coll., Vol. XLIV, p. 80. 



" Kaunhowen, F., 1897, Pal. Abhandl, Achter Bd., p. 82, Taf. X, figs. 1, 2, 3, 4. 



