AND OTHER FAMILIES. 85 



Hab. Mexico, Professor Vanuxem. 



My Cabinet. 



Cabinet of Professor Vanuxem. 



Cabinet of the Academy of Natural Sciences of Philadelphia. 



Cabinet of P. H. Nicklin. 



Diam. 1-2, Length 2-5 inches. 



Remarks. — Among the shells brought from Mexico by professor 

 Vanuxem, was this fine Achatina, which belongs to Lamarck's second 

 division of this genus. It very closely resembles the Bmcinum striatum 

 (Chem.), Polyphemus glans* (Say), Glamlina (Say). It differs from 

 it in having crenulated sutures, and in having fine transverse lines, as 

 well as longitudinal striaj. The indistinct opake white spots, which 

 are more frequent on the front of the body whorl, are, I believe, pecu- 

 liar to this species. It is larger by one-third than any individual of 

 the striata which I have seen. 



In concluding these descriptions and observations, I will take ad- 

 vantage of the opportunity to express my thanks to those gentlemen 

 who have kindly assisted me with new shells and rendered other 

 friendly offices. Among these I have been particularly obliged by 

 Philip H. Nicklin, Esq., William Cooper, Esq. and professor Troost. 

 To the Academy of Natural Sciences of Philadelphia an acknowledge- 

 ment is due, for the liberal and unhesitating vote which it passed, to 

 permit me to describe for our Transactions the new species in their 

 splendid and highly useful collection. 



I will take this opportunity also to correct the habitat of the Unio 

 brevidens (Vol. IV. page 75), which professor Troost thinks has not been 

 found in the Ohio, but only in the Cumberland. The specimen which 

 Mr Cooper kindly gave to me to be described, came, I believe, originally 

 from professor Troost. The specimen figured was not more than half 

 grown. The older individuals usually have an arched ridge along the 



* Cochlicopa rosea (Fer.). It should now be called Achatina striata, unless the generic 

 name be changed, the propriety of which I doubt. 



VOL. V. W 



