FIBULA. 175 



Shell elongate, conical, spiral angle regular; whorls ten to twelve, flat to 

 subconvex, narrow, smooth ; a slightly raised belt in the upper part of each 

 whorl gives a faint appearance of turriting ; suture close. 



Body-whorl rather short, subtumid, rounded, and smooth. In some specimens 

 there is a slight indication of an umbilicus ; columella short and straight. Aperture 

 subquadrate, with a thin rounded outer lip and a square base strongly notched at 

 its junction with the columella. 



Relations and Distribution. — The small size of all specimens hitherto found 

 may be deceptive, since Gasteropoda in the Lincolnshire Limestone are usually 

 small. The narrowness of the whorls seems to distinguish it from any other 

 species hitherto referred to Fibula. Somewhat rare in the Lincolnshire Limestone 

 at Welclon. 



105. Fibula canina, Hudleston, 1884. Plate XI, figs. 2 a, 2 b. 



1884. Cerithium (?) caninxtm, Hudl. Geo]. Mag., dec. iii, vol. i, p. 107, pi. iv, 



figs. 1 and 2. 



Description : 



Length of a large specimen . . .51 mm. 



Width . . . . .21 mm. 



Ratio of body-whorl to entire shell . . 35 : 300. 



Spiral angle . . . . .32°. 



Shell subelongate, conical, with perhaps a rudimentary umbilicus ; spiral 

 angle regular. Whorls about ten, smooth, somewhat tumid towards the centre, 

 and separated by a suture of moderate depth. Wavy longitudinal lines, appa- 

 rently lines of growth, are seen in some specimens. 



Body-whorl rather more than one-third the total height of the shell, rounded, 

 and smooth ; aperture quadrate, with some traces of an anterior notch. Other 

 indications wanting. 



Relations and Distribution. — When one has to deal with a doubtful species it is 

 as well to place it in a doubtful genus. The nature of the matrix may have 

 somewhat modified the available specimens. The number of whorls seems to be 

 few for such large shells. F. canina has some resemblance to Fibula (Chemnitzia) 

 phasianoides, M. and L. (pi. ix, fig. 5), whilst it has less resemblance to the types 

 of Piette. We are also reminded of Fibula Gastaldi, Gemm., (' Faune Giuresi,' 

 p. 281, pi. 22, fig. 55). Rare in the Yorkshire Dogger. 



