14 LIMACHLE. 



History, Vol. IX. p. 486, to include an animal resembling 

 the type of Tebennophorus, and so far as we can judge 

 by the description, corresponding with it generically. 

 Whether either of these genera will be received, is un- 

 certain, and will depend of course upon the opinion of 

 other naturalists, after the animals shall be fully known. 

 If neither of them should be adopted, the characters of 

 Limax will need an entire revision and enlargement. 



The following formula shows the generic strength of 

 the family in this country. 



!VAGINULUS, 

 TEBENNOPHORUS, 

 ARION, 

 LIMAX. 



These are the only genera hitherto discovered. Of 

 these Vaffinulus is a tropical genus, and barely touches 

 the most southern point of the United States, rendering 

 it probable that it was introduced from the West Indies. 

 Tebennopliorus, before the publication of Dr. Cantor's 

 Memoir, was supposed to be peculiar to the United 

 States and Canada. It must now be at least doubtful 

 whether it is exclusively an American genus. Avion is 

 certainly an imported genus, owing its introduction to 

 our commercial relations with Western Europe. Limax 

 is also an introduced genus, so far as regards two out of 

 three of its known species, and perhaps as to the third. 

 We have then, not even one genus which is unquestion- 

 ably indigenous to our territory, 



