Pulmonifera of Maine. 



39 



Isthmla milium, Gould. 



Mr. C. B. Fuller has met with this species in an open field near 

 the coast. 



Isthmia simplex, Gould. 



This species is generally distributed throughout the southern 

 portions of the State, though by no means common. 



AURICULIDJE. 



AURICULIN^. 



Carychium exiguum, Say, {Fig. 97.) 

 Occurring throughout the State, more abundant in the interior; 

 generally preferring low wet ground. 



Lingual membrane having numerous rows of plates, each 

 row having one central flanked on each side by sixteen laterals ; 

 central plate long, narrow, having one minute pointed denticle ; 

 first four laterals armed with one short rounded denticle, next 

 six laterals bidentate, the rest which probably comprise the 

 uncini, broad simple recurved plates. Plates translucent, den- 

 ticles light horn color. {PL 10, Fig. 99.) 



This dentition has a strange similarity to that of 

 Punctum minutissimum, in the form and arrange- 

 ment of plates and the light horn color of the denticles. 



Fig. 97. 



Though the resemblance between this species and the Cary- 

 chium minimum of Europe is very close, and has 

 often been remarked upon, they have never been 

 united, either by American or (to my knowledge) 

 European writers. The Carychium minimum as 

 will be seen by Figure 98, is more inflated than 

 our species, and the aperture is more oblique also ; 

 the parietal tooth is quite prominent in C. mini- 

 mum as compared with our species; the palatal 

 tooth in C. exiguum is nearer the base of the 

 shell, and the columellar tooth is a slight fold only 

 within the aperture. 



Fig. 98. 



