154 



AURICULA CEA. 



In the " Genera of Recent Mollusca," by Henry and 

 Arthur Adams, the following division is made of the air- 

 breathing Gasteropoda : 



ORDER. 



SUBCLASS PULMONIFERA. 



SUBORDER, 



Inoperculata, 



Geophila, 



Limnophila, 

 Thassilophila, 



Ectophthalma, 

 Operculata, < Qpisophthalma, 

 { Prosophthalma, 



FAMILY. 



{ Oleacinidte. 



Testac'ellidse. 



Helic-idce. 



Lhnacidje. 



Stonopidae. 



Avion id re. 



Janellidffi. 



Veronicellidoe, 

 [ Onchidiidse. 

 \ Kllobiidre. 

 I Limnseidse. 



Amphibolida?. 



Siphonaridse. 

 ( Cyclophoridae. 

 / Heliciniiln?. 



Truneatellidse, 



Assiminidae. 



The family Ellobiidae corresponds to PfeifFer r s family 

 Auriculacea. 



This family has been noticed only by the following 

 American authors. The treatment of the various genera 

 and species will be found in their respective synonymy. 



In 1841 Gould placed the genus Auricula in the Lam- 

 arkian family Colimacea. 



DeKay in 1843 places the Auriculidce as the third 

 family of Pulmobranchia. He unites all the species de- 

 scribed in his Zoology of New York in the genus Auri- 

 cula. 



Stimpson in 1851 catalogues the family Melampidce, 

 comprising the genera Melampus and Carychium. He 

 was the first American to remove Carychium exiguum 

 from the genus Pupa. 



The Auriculacea are easily distinguished from the other 

 inoperculated land Mollusks. They are furnished with 

 but one pair of non-retractile tentacles, on the inner 

 base of which are situated the sessile eyes. The head 

 is extended beyond the tentacles into an obtuse, rounded, 



