112 J. Starhie Gardner — Cretaceous Gasteropoda. 



against the subdivision of the family of TurritelUdce. Briefly stated, 

 the argument is, that because there are transitional forms in the older 

 Tertiaries between the Scalidis and Turritellidce, and also in the 

 recent genus Eglisia, the families cannot be divided ; but most con- 

 chologists would j^lace Eglisia with the Scalidce, and not, as Adams 

 does, in the Turritellidcd ; and the remainder of the argument, if carried 

 to its logical conclusion, and if it were adopted by workers in the 

 older rocks, would lead to the re-union of nearly all the families of 

 Gasteropoda. 



It must not be forgotten, and it is evident that, to admit the new 

 group, the description of Scalidm must be slightly modified; the 

 essential character of the orbicular or ovate mouth with continuous 

 border, however, remains. 



Ptrgiscus, Philippi. 



Shell elongated, many-whorled, ribbed ; aperture oblong or ovate, 

 peristome incomplete ; columella straight, simple, without plaits or 

 teeth. 



Pyegiscus GrATJLTiNus, J. S. G. Gault, Folkestone. 

 Plate IV. Figs. 8, 9, 10. 



Shell elongated, thick, angle about 20"^ ; whorls ten, flattened, apex 

 rather obtuse (Plate lY. Fig. 9rt), with slightly ventricose whorls; 

 ribs ten to twelve, straight, rounded, prominent, extending quite to 

 the sutures ; strias fine and regular, seen under a lens to be crossed by 

 transverse lines (Fig. 96) ; sutures distinct. Mouth rounded, a little 

 angular and somewhat produced in front ; columella straight ; no 

 keel on the last whorl. 



This shell, which has hitherto escaped notice, or been considered 

 as the young state, or a variety of Sc. Clementina or Dupiniana, is 

 not uncommon, and may readily be distinguished from others of the 

 Gault by. its flattened whorls and obtuse appearance. The large 

 specimen figured is from the collection of Mr. Craven, and is a 

 magnificent example, and of most unusual dimensions ; the smaller 

 figures are from fossils in my collection. 



Ptrgiscus Woodwardii, J. S. G. Upper Greensand. Blackdown. 



Plate III. Fig. 19. 



Shell elongated, angle 18°; whorls numerous, flattened; ribs 

 fifteen, angular, prominent and slightly bowed, extending quite to 

 the sutures ; strise fine and indistinct ; mouth pyriform or sub-quad- 

 rate ; lips thin. The ribs on the last whorl are not very regular, and 

 become attenuated near the columella ; there is no spiral keel. 



Described from an unique specimen, lately in Dr. Bowerbank's 

 collection, now in the British Museum. I have named it after the 

 Editor of this Magazine, to whose courtesy I am indebted for fre- 

 quent opportunities of examining the extensive collections not ex- 

 posed at the British Museum. 



Pyrgiscus tenuistriatus, Seeley. 

 Described as Ceritliium tenuistriatum in the Annals and Mag. of 



