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AMERICAN JOURNAL 



having less expanded and produced cutting edges. Lower edge 

 of base of attachment fringed. Our figure on phite 9, gives one 

 central and one lateral tooth. 



Achatiua lUsciatii. 



The figure here given was drawn by Dr. Leidy for the " Ter- 

 restrial Mollusks." (Vol. II., p. 270.) It represents the ex- 

 treme laterals. There are no true uncini, or, judged bj the 

 lingual membrane of A. virginea, it is more correct to say there 

 are no laterals. 



It will be seen that Achatina fasciata resembles in its lingual 

 dentition more nearly Orthalicus zebra, given below, than 

 Achatina virginea given above. 



Orthalicus zebra, Mlill, (PI. 9, fig. 2.) 



The lingual membranes examined are from specimens received 

 by the Smithsonian Institution from the Sierra Madre, (See 

 Land and Fr. W. Shells of N. A., Part L, p. 217, fig. 371.) 



Central teeth long and narrow, the lower edge strongly cor- 

 rugated ; about three-fourths of the distance from the upper to 

 the lower edge of attachment springs a gouge-shaped cusp, with 

 convex cutting edge projecting considerably beyond the tooth. 

 Laterals similar in shape, but unsymmetrical to the centrals, also 

 rather broader, with more expanded cusps, whose cutting edge is 

 convex. There seems no distinct uncini, but as the laterals 

 become removed from the central line they are more distinctly 

 separated, and bear the side spurs described in the membrane of 

 Achatina virginea and A. fasciata, above. 



There are about 50 — 1 — 50 teeth in each row, arranged en 

 chevron. 



The jaw of this species has been figured by us (in Land and 

 Fr. Water Sh. of North Am., Part I., p. 215, fig. 367.) 



The lingual membrane very nearly resembles that of Achatina 

 fasciata, described above. 



We have said there are no true uncini, but studied in the light 



