EUCYCLUS. 83 



Purpurina ornata (6, 25, 28). Turbo elaborates (25, 28, 43). 



Purpurina condensate, (50). * Turbo funiculatus (6, 28, 50). 



Botella expansa (G). 

 Of these, for Amberleya armigera see Eucyclus armiger. Littorina phillipsi has 

 not been seen distinct from Eucyclus armiger. It belongs originally to the 

 Scarborough Limestone. Purpurina ornata was the name assigned to the shell 

 afterwards described by Lycett as Amberleya armigera. Purpurina condensate 

 has been stated to be the same as the Cornbrash form previously referred to 

 Turbo elaborates, which latter form will be found here under the first title. Turbo 

 funiculatus is here described as Littorina cassius and Botella expansa as Helicocryptes 

 apertior. 



Family Tuociionbmatid.e. 



This name is used by Zittel for a number of genera which are considered of 

 doubtful position with respect to the Littorinidae, Turbinidse, or Purpurinidge, but 

 agree in having their whorls ornamented by spiral keels. 



Genus EUCYCLUS, Deslongchamps. 



Established by Deslongchamps in I860 (' Bull. Soc. Linn. Norm.,' vol. v, p. 141) 

 as follows : " Pyramidate, or nearly turriculate. Shell very thin ; whorls rounded, 

 increasing regularly ; suture imbedded ; surface covered with various transverse 

 [spiral] folds, some more developed than others and forming one or more keels, 

 crossed by numerous longitudinal lines. Base oblique, more or less rounded with 

 concentric [spiral] folds, non-umbilicated ; mouth oval, right lip semicircular, thin ; 

 left lip not seen on the return of the spire, but resting on the columella, which it 

 thickens and enlarges, unites at a more or less open angle, but makes no notch 

 with the right lip." 



A large number of Jurassic species correspond with this generic description, 

 amongst them the Cornbrash form, which must be referred to it, though it has been 

 called Amberleya. The original diagnosis of the latter genus does not suit the 

 species referred to, as will be seen by the following quotation, in which the differ- 

 ences are italicised : " Shell turreted, turbinated, apex acute ; whorls flattened above, 

 convex and nodulated beneath, the last whorl ventricose ; aperture ovate, entire, 

 inner lip thickened and nearly covering a small umbilicus; sutures deeply 

 impressed; no columella." The shells answering to the description of Eucyclus 

 were at the same time referred to Littorina. It was only later that Lycett ex- 



