ENDODONTA. 23 



Endodonta stock, but the elevated contour and the aperture arma- 

 ture render it quite distinct in aspect. 

 E. pagodiformis Smith, viii, 86. 



bilamellata Pfr. not Sowb. 



? oparana Beck (undesc.) 



Subgenus LIBERA Garrett, 1881. 



Libera GRT., Journ. Acad. Nat. Sci. Phila. (2), viii, p. 390; ix, 

 p. 33. Not " Cephalopoda Libera " DEHAAN, Monographic Ammo- 

 niteorum et Goniatiteorum, p. 18 (1825), which was not proposed as 

 a generic name, and is in no sense such. 



Shell depressed, widely umbilicated in the young, the umbilicus 

 strongly constricted in adults to form a pouch- like cavity, in which the 

 eggs are carried. Whorls 7-9, closely-coiled, the last generally 

 angular. Aperture subrhombic, provided with folds within ; lip 

 thin, sharp ; the columellar margin dilated, emarginate. Type E. 

 subcavernula, pi. 5, figs. 45, 46, 47. 



Animal small, ovoviviparous ; eye peduncles long and slender, 

 tentacles small ; foot short, narrow, pointed behind. 



Genitalia entirely simple, lacking all accessory organs (L. bursa- 

 tella, teste Semp. Phil. Reise, p. 135.) 



Jaw of L. bursatella distinctly striated, narrow, as if composed of 

 fully 20. narrow lamellae; entirely similar to that of P. rotundata 

 Mull. 



Radula consisting of 15-1-15 (recedens) to 10-7-1-7-10 (tumulo- 

 ides) teeth. Centrals tricuspid. Laterals lacking the entocones or 

 having it excessively small. Marginal teeth having a long bifid 

 inner cusp (entocone plus mesocone) and a small ectocone (pi. 9, 

 fig. 34, E. recedens Grt. ; pi. 9, fig. 26, E. tumuloides Grt.) 



The prominent feature of this radula is the lack of entocones on 

 the lateral teeth. The jaw corresponds exactly with that of the 

 typical Charopas. Semper has examined the animal of bursatella ; 

 Binney the teeth of tumuloides, and I have examined the radula 

 of recedens. 



This group is distinguished from Endodonta and other toothed 

 Patuloids by the constriction of the umbilicus. The young (pi. 5, 

 fig. 48, E.fratercula Pse.) contained in the umbilical pouch consist 

 of about H rounded, ventricose whorls, which are regularly and 

 finely rib-striate, showing no trace of spiral stride. The figure shows 



