LYMN^EID^E OF NORTH AMERICA. 



167 



Length. Breadth. Aperture length. 



21.50 12.00 14.00 



19.00 12.00 14.50 



16.00 8.50 11.40 



14.00 7.75 9.50 



21.00 11.00 15.50 



13.00 7.00 9.00 



10.00 6.50 7.00 



19.00 11.00 14.00 



12.00 7.50 9.00 



20.50 12.00 15.00 



14.00 8.00 10.00 



TYPES : Columella Say, Academy of Natural Sciences, Philadel- 

 phia, three specimens, No. 58791 ; columellaris C. B. Adams, Amherst 

 College ; navicula Val., location unknown ; Succinea pellucida Lea, eight 

 specimens, No. 117913, and Succinea zvilsoni Lea, one specimen, No. 

 121066, Smithsonian Institution ; macrostoma Say, Academy of Nat- 

 ural Sciences, Philadelphia, three specimens, No. 58582; acuminata 

 C. B. Adams, Amherst College. 



TYPE LOCALITY: Columella Say, type locality not mentioned by 

 Say (probably near Philadelphia) ; macrostoma Say, Cayuga Lake, 

 N. Y. ; acuminata Adams, New Bedford, Mass. ; navicula Val., Phila- 

 delphia, Penn ; Succinea zvilsoni, Darien, Ga. ; Succinea pellucida, type 

 locality not given. 



ANIMAL: Almost transparent, with a short, wide foot, bluntly 

 rounded behind ; head separated from foot by a constriction ; tentacles 

 short, thick, triangular, .transparent; color dirty white, darker on the 

 body, which is covered with white spots, seen through the transparent 

 shell; edge of mantle transparent; head above lilac-tinted; the head 

 is not much in advance of the edge of the shell when the animal is 

 in motion ; the animal appears much too large for the shell. Length 

 of foot, 8.00 ; width, 5.50 mill. 



JAWS: Median jaw wide and low, arched, about three times as 

 wide as high; lower margin with a wide, bluntly rounded median 

 projection. (PL VI, fig. C.) 



RADULA: FORMULA (plate VII, fig. B) : !+f+Y-+i+y+i+f 

 (35-1-35) ; central tooth with a wide reflection, the cutting point 

 broadly spade-shaped ; lateral teeth with a quadrate base of attachment ; 

 reflection rather wide, reaching below the base of attachment, tricuspid, 

 the mesocone the largest ; all cusps wide and spade-shaped ; the second 

 lateral has the entocone nearer the distal extremity, the ectocone be- 

 coming higher on the reflected portion ; the eleventh and twelfth teeth 

 are modified and connect the lateral with the marginal teeth, a second 



