I 
» 
On thè genus Pompholyx and its allies, with a revisioni of thè 
Limn^id^ of authors. 
By William H. Dall. ■ 
Reprinted from thè Armala of thè Lyceum of Naturai History, Voi. IX., March , 1870. 
The receipt, through thè kindness of Mr. Harford, of a nnra- 
ber of speeimens of Pompholyx enables me to correct an error 
into wliich I had been led, and to add something to our knowl- 
edge of this singular mollusk. 
In 1866, Mr. William M. Gabb furnished me vith drawings 
and descriptions of thè soft parts of thè animai of P. effusa, 
Lea, taken from life. In both, it was represented as possessing 
two pair of eyes; one pair at thè inner basis of thè tentacles 
(as in Physa) and one at thè tips of thè tentacles (as in 
Vertigo). 
On this point Mr. Gabb was positive, and, relying on bis 
accuracy, I separated this mollusk from thè (jther fresh water 
pnlmonates, provisionally, in a sub-familv by itself. 
1 
