304 Rev. R. T. Lowe on Melampus, Sfc. 



my observation have an elongated foot, truncated in front, and attenuated 

 behind ; the head and muzzle not probosciform, and the tentacula long 

 and filiform, seated on each side the head or neck much as in Helix. The 

 absence of an epidermis, and the plain (not spiral) operculum distinguish 

 the shells from the Melania, to which indeed they have in sculpture, shape 

 and outline considerable resemblance : and it is probable, that when the 

 animal of this last named genus shall be accurately made known, Trun- 

 catella will bear the same relation to it that the marine Littorina does to 

 the true fluviatile Paludina. With Cyclostoma, it has no connection 

 whatever, except in the way of analogy. 



Funchal, Madeira. 

 Nov. 14, 1829. 



EXPLANATION OF PLATE XIII. 



Fig. 1. Animal of 7Vfe/aw/»M5 cequalis a. natural size; seen from above. 



2. Ditto seen beneath, as crawling up a glass. 



3. Ditto seen from above. 



4. Ditto seen beneath ; shewing the details of the open mouth, 



the upper jaw, &c. 



5. The shell. 



2, 3 and 4 all more or less magnified. 



6. Shell of Melampus exiguus. 



7. Ditto. 



8. Animal of Pedipes afra ; natural size. 



9. Ditto seen beneath ; shewing the double foot as it appears when 



the animal is in the act of drawing up the posterior por- 

 tion to the anterior : the space or hollow between 

 these never appears wider than here represented. 



10. Ditto shewing the appearance of the foot when at rest. 



1 1 . Ditto seen above when crawling. 



12. The shell. 



9, 10 and 11 all more or less magnified. 



