NERIN^A. 221 



whorls, later ones perfectly smooth. The only salience throughout the long and 

 narrow spire is a slight spiral band on the posterior margin of each whorl. 



Body-whorl smooth, angular, elongate; aperture oblong, with a canal rather 

 long for the genus and slightly deflected. Section shows seven folds, arranged on 

 the bacillus- or Oppelensts-Tplan. 



Relations and Dlstrihntion. — In its narrow cylindrical outline and in the 

 relative height of the whorls this species resembles P^//f/. hacillus, from which it is 

 separated by the complete flatness of the whorls and the absence of any promi- 

 nence at the sutures. Rare in the Pea-grit of Longfords. 



157. Nerin^a (Ptygmatis) consobrina, Witchell, 1887. 



1887. Nerinjea consobeina, Witchell. Vol. cit., p. 33, pi. i, figs. 10, 10 a. 



As I have not seen the type, and never found a specimen which answers to this 

 description, the species is inserted on the authority of Mr. Witchell alone. 



He says that it differs very little in its internal structure from N. OiJ-pelensis, 

 but it has a more conical figure and the whorls are higher. Found at Longfords 

 in the Pisolite. 



158. Nerinjua {Ptygmatis) velox, Witchell, 1887. Plate XVI, fig. 1. 

 1887. Neeinjea velox, Witchell. Vol. cit., p. 34, pi. ii, fig. 3. 



Description : 



Spiral angle (slightly obtuse) . . .10°. 



Height of whorl to width . . . 1 : 1*5. 



Average length . . . .75 mm. 



Shell cylindro-conical, dimorphous. Whorls about thirty, of which the posterior 

 two-thirds are deeply excavated and much thickened at the sutures. Ultimately 

 the whorls become flat and without any sutural prominence. The whorls are 

 extremely short, and no trace of spiral ornament has been detected in the specimens, 

 though it is probable that the posterior whorls of the spire were spirally striated. 



The aperture is nearly square, with a short and not very reflexed canal. 

 Section, seven folds, identical with that of Ptyg. Oppelensis. 



Relations and Distribution. — From Ptyg. Oppelensis this species differs in its 

 more conical form, and in the excessive flatness of the anterior whorls. Rare in 

 the Oolite Marl horizon of Swift's Hill and Longridge. 



