No. 2327. THE ANNULARIJDAE— HENDERSON AND BARTSCH. 57 



G^. Breathing siphon not reflected into nor closing the umbilicus. 



Subgenus Torrellisca. 

 A^. Lamellae not absent or obsolete on the operculum. 

 B^ Lamellae not reenforced by strong calcifications . . . Subfamily Adamsiellin^. 



C^ Axial and spiral sculpture about equal Subgenus Adamsiella. 



D'. Peristome almost or quite adnate to the last whorl. 



El. Axial riblets gathered into tui'ts at the summit Group mirahilis. 



W. Axial riblets not gathered into tufts at the summit Group pvlchrior. 



D^. Peristome not almost or quite adnate to the last whorl. 



E. Last whorl decidedly solute Group viovstro.m. 



(y. Axial and spiral sculpture not equal. 



D'. Axial sculpture much stronger than the spiral Subgenus Adamsiellops. 



E'. Axial riblets gathered into tufts at the summit Group antiguense. 



E^. Axial riblets not gathered into tufts at the summit Group ignilahre. 



B^. Lamellae reenforced by strong calcifications Subfamily Annularinae. 



C. Lamellae placed obliquely upon the basal plate Genus Annularia. 



D'. Puncture or slit absent. 



E'. Spiral sculpture absent Subgenus Amiularisca. 



E^. Spiral sculpture not absent. 



F'. Spiral sculpture confined to the umbilicus Subgenus Annular osa. 



F^. Spiral sculpture not confined to the umbilicus. 



G'. Axial sculpture consisting of almost uniform riblets. 



II*. Peristome broadly expanded, thin Subgenus Annularia. 



I». Shell turbinate Group fiv-ihriatula. 



V. Shell not turbinate. 



J'. Shell ovate-conic Group lincina. 



J'-. Shell not ovate-conic. 

 K. Shell elongate-conic. 



L'. Spiral sculpture strong Group illustris. 



L-. Spiral sculpture weak Group lachneri. 



H^. Peristome not broadly expanded. 



I. Peristome thickened Subgenus Annular ita. 



G^. Axial sculpture not consisting of almost uniform riblets. 

 H. Axial sculpture consisting of slender lamellae with fine axial 

 threads between them Subgenus Annularella. 



I'. Shell turbinate ( 



roup yunquensis 



I^. Shell ovate-conic Group bertini. 



D^. Puncture or slit present. 



E^ Puncture without external siphon, axial ribs articulate 



Subgenus Annidarops. 



E^. Puncture with external siphon, axial ribs not articulate 



Subgenus Annularodes. 

 G^. Lamellae not placed obliquely upon the basal plate. 



D'. Lamellae placed vertically upon the basal plate Genus Blaesospira. 



E'. Shell ovate-conic. 



FK All whorls solute Group echinus. 



F^. All whorls not solute Group pretrei. 



E^. Shell not ovate-conic. 



F. Shell depressed helicoid Genus Abhottella. 



D^. Lamellae not placed vertically upon the basal plate. 



E'. Lamellae reflected to parallel the basal plate Genus Tvdora. 



F'. Lamellae marked by feeble oblique riblets. 

 G'. Lamellae almost flat. 

 H'. Breathing notch, slit, or pore absent. 



