210 



Localities. — Eocene. River Murray Cliffs, near Morgan ! ; 

 Muddy Creek ! (J. Dennant). 



Var. ? The example from Muddy Creek is of the length of 

 about five and a-quarter inches and has the inflated back of the 

 type, but otherwise it presents differential characters, whicli might 

 from an extreme point of view be regarded as of sectional value, 

 though I am inclined to consider them as the result of individual 

 variation of an extreme senile growth. 



The anterior canal is longer and slightly curved upwards, but 

 the basal flanges are broad and acutely rounded on the edge ; 

 there are no basal tubercles. The posterior canal is the same, 

 except that the basal flanges are flatly, broadly, and thinly ex- 

 panded. But the chief differences belong to the aperture ; on the 

 columella-side the base is broad and flatly-rounded to the inner 

 margin, which carries about thirty short, convex, dental ridges, 

 about equal in width to the interspaces ; the outer lip, instead of 

 being convexedly inflected, is flat or slightly concavedly-declinous 

 from the exterior to the inner margin, on the latter of which 

 there are about thirty sharply-rounded narrow dental ridges be- 

 coming effaced at from one-half to one-third the width from the 

 inner margin. Thus the chief exceptional characters are the 

 short teeth and flat inner lip, replacing the dental-sulcations on a 

 steeply-inclined area, in which regard this variety makes a con- 

 necting link betw^een C. eximia and C. umhilicata. 



Diynensions.—'Length, 135; width, 75; height, 55; length of 

 anterior canal, 35 ; of posterior canal, 25. 



16. Cyprsea toxorhyneha, spec. nov. 



Resembles C. eximia, but differs by its high steep-sided back 

 and bent canals. 



The back is very ventricose, abruptly rounded to the flat 

 almost-concealed spire, abruptly tapering to the anterior canal ; 

 the left side is very steep, but the right is less abrupt. The pos- 

 terior canal, viewed from above, is very broad at the base, wdth 

 thick rounded margins, the beaked-portion is broadly convex, not 

 upturned though slightly bent ; its margins are much thickened, 

 the inner side extends beyond the other ; there is no basal 

 tubercle. The anterior canal is supported by a thick round- 

 edged extension of the base, and has no basal tubercles ; the canal 

 is cylindroid, almost closed, much upturned and slightlv bent to 

 the left. 



Dimensions. — Total length, 94 ; length from spire to base of 

 anterior canal, 55 ; width, 47 ; height, 43. The relative propor- 

 tions to the length of the shell, exclusive of the canals, of the 

 tw'O species are as follows : — 



C. eximia — ^Length, 100 ; width, 82 ; height, 70. 



C. toxorhyneha — Length, 100; width, 85; height, 78. 



