212 GASTEROPODA OF THE INFERIOR OOLITE. 



the forms next described may be varieties, and the species described as Longford- 

 ensls (PI. XlII, fig. 5) resembles it in the anterior constriction of the whorls. 



147. Nerin/EA, species or variety. Plate XIV, fig. 15. 



Description. — From a fragment 20 mm. in length. Spiral angle about 5°. 

 Shell cylindrical, turrited. Whorls moderately high with a deep median furrow, 

 and separated by a wide suture ; in the lower whorls a spiral line is seen in the 

 furrow, but other ornaments, if any, are obliterated. Section triplicate or 

 quadruplicate. 



Relations and Distribution. — There may be a considerable amount of deception 

 produced by mineralization in this case. This form possesses a certain degree 

 of resemblance to the later stage of N. cingenda, such as fig. 13 c, but the 

 central furrow occupies the position of the median belt in the Yorkshire species, 

 hence I would give it the provisional term of '' pseudocingenda." The specimen 

 is of interest as comiug from the Lower Limestone of the Cotteswolds near 

 Holcombe Mill, which occupies a position below the Pea-grit and yet above the 

 recognised Opalinus-zone. 



148. Nerin^a subcingenda, sp. nov. Plate XIV, figs. 16 a, 16 h. 



Description : 



Spiral angle (regular) . . . 10°. 



Height of w^horl to width . . . 1 : 1'4. 



Usual length .... 30 — 35 mm. 



Shell cylindro-conical, strongly turrited. Whorls twelve to fourteen, much 

 excavated anteriorly, flat and prominent posteriorly. Three spiral lines are con- 

 spicuous and rather wide apart in the anterior whorls ; and finer intermediate 

 spirals probably also exist. These decussate with lines of growth. 



The body-whorl, in addition to the thin spiral raised lines, has a sharp anterior 

 keel ; the base is drawn out and ornamented with numerous fine spiral lines of 

 rather unequal strength, partially decussating with lines of growth. Aperture 

 rhomboidal, with a short and wide reflexed canal. Section unknown. 



Relations and Distribution. — The peculiar mineralization of the Dogger fossils 

 renders a close comparison almost impossible. This species or variety is of shorter 

 habit and more conical than average specimens of N. cingenda, and the whorls are 



