211 



contracted neck ; provided with a single pair of eyes on its 

 posterior or occipital region, if we may apply to mollusks the 

 terms used in describing Vertebrata. Snout slightly notched. 

 The body of the animal swollen and contracted, terminating 

 posteriorly in a pointed tail. 



For the Danish species I shall retain the specific denomination 

 under which it has been made known, and call it henceforth N. 

 limacina^ the color of which is of a uniform greenish brown, 

 paler beneath. 



The species from Boston Harbor is less than a line in length ; 

 its body and head are not quite as much separated as in N. lima- 

 cina. It has a pale, reddish hue, with transverse bands of 

 white, which have suggested the specific name of N. zonata. 



In the third volume of the Proceedings of the Society, p. 264, 

 I have described, under the name of Vortex Warrenii^ a species 

 of marine Planaria, which, after mature reexamination, I am 

 satisfied constitutes a new genus, which I propose to call 



FoviA Girard. 



Body elongated, sides linear. Anterior extremity subtrun- 

 cated, posterior one rounded. The organization of this genus I 

 shall illustrate in my monograph of these animals. I have 

 already alluded (p. 363, Vol. III. of the Proceedings) to its 

 peculiar mode of generation, which consists in bringing forth 

 living young. The species I shall continue to designate under 

 the name of F. Warrenii. It occurs abundantly on Chelsea 

 Beach, Mass. 



Vortex Candida^ described at the same time, has been rede- 

 scribed since by Dr. Leidy,* under the name of Bdelloura 

 parasitica. The genus Bdelloura I adopt, but the species must 

 retain its prior name and be called B. Candida Girard. 



Among the freshwater Planaria, which I have seen in the 

 vicinity of Washington, there is an undescribed species which 

 ranges within the limits of the States of Pennsylvania, Maryland, 

 and Virginia, and belongs to my genus Dugesia. I propose to 

 call it 



Dugesia Foremanii Girard. It is the largest species hitherto 

 ^ Proc. Acad. Nat. Sc. Philad. v. pp. 242, 289. 



