384 



MISj> MC1>0>"ALI> A>'D DE. TEUEMAy OiN 



vol. 1 



XXVll. 



the last whorl thev become finer, and show a marked double curve 

 with the development of incipient tubercles where they are crossed 



by the equally line spirals (fig. 



Fig. 21. — Katosira transgressa, 

 sj). nov. SoJot 1/2^6 enlarged. 



[a = about the seveutli Ti-liorl; 

 6= last whorl. ^ 



This form differs from all other 

 niembers of the Loxonematidse 

 that Ave have considered, in pro- 

 ducino' tiny tubercles : it has 

 undoubtedly developed from 

 some group resembling K. cf. 

 youngi, and is not in any way 

 related to the species of Pro- 

 ceritliium which it comes to 

 resemble in some degree. K. 

 comjyJicata (Tate) is a species 

 with similar affinities. 



Locality and horizon. — 

 The holotype is a specimen 

 from the Lower Lias {oxgnotus 

 zone ) from the railway-cutting 

 (Gr. C. R.) near Hillmorton, 

 Rugby. 



Spiral 



Sutural 



angle. 



angle. 



ik" 



105° 



Katosiea co>'ci>'yA, sp. nov. (PI. XXII, fig. 4.) 



Dimensions of holotype. 

 Lengtli. Breadth. T,ength of spire. 



20 mm. 25 per cent. 75 per ceut. 



Holotj-pe : A specimen in Mr. J. W. Tntcher's collection, Xo. 1012. 



A slender form, with convex rather tumid whorls, sej)arated by 

 narrow and deep sutures, the ornamentation consisting of fine, 

 regular, and curved axial lines crossed by spirals which are pro- 

 minent near the posterior suture. 



Development. — The upper whorls are not clearly preserved, 

 but apparently have straight and somewhat oblique axial ribs, 

 Avhich increase in number and degree of curvature ; equally-spaced 

 spii-als are recognizable at a comparatively early stage, and on the 

 penultimate whorl these are strongest near the posterior suture. 

 On the last whorl the axials show a curve resembling that of 

 Katosira transversa, and there is a very slight tendency to pro- 

 duce an imbricate whorl. 



This form appears to be related to K. cf. youngi ; but it differs 

 in the finer ribs (about thirty to a whorl), in the greater curve of 

 the axials, and in the shape of the whoi'l. 



Locality and horizon. — The holotype is a specimen from 

 the Lower Lias {armatus zone), Clandown Quarry, Radstock 

 f Somerset). vSomewhat similar forms were found at the same 

 horizon at Binces" Lodge, Wilton (Somerset). 



