14 BemarTcs on Certain Species of 



Mr. Lea has kindly allowed me to examine his original spe- 

 cimen, which diifers from mine only in having the parietal 

 tooth somewhat more emarginate. 



H. Troostiana is very closely allied to U.fatigiata Say, from 

 which I separate it with some hesitation. In its fresh state it 

 has a thin, sparingly hirsnte epidermis. I have moreover two 

 specimens in my cabinet (both hirsnte), which are as acutely 

 carinated as fatigiata, w^ith the strise as prominent below as 

 above, — (in one more numerous), but both having the parietal 

 tooth of Troostiana. 



I am not altogether satisfied with the validity of Shuttle- 

 w^orth's remark, that the superior tooth in fatigiata is larger 

 and more conspicuous than in Troostiana. 



This species has the same tubercle within the last whorl as 

 H. fatigiata. 



The following are the measurements of my specimens, — of 

 one received from Judge Tappan, and agreeing with Mr. Lea's. 



Diam. maj. 8, min. 7, alt, 3. 



Var. h. — carinata. Diam. maj. 9, min. 8, alt. 3. 



Yar. c. — minor. Carinate, and with striae below more nume- 

 rous than above — an additional one being intercalated between 

 nearly every pair passing over the carina. 

 Diam. maj. 8, min. Y, alt. 3. 



Mr. W. G. Binney, in his "Kotes on American Land Shells," 

 remarks on the plates in the " Terrestrial Mollusks" in the 

 following terms, — " Helix plicata Say. PL xxxix. Fig. 2. 

 Mr. Say's type is preserved in the collection of the Academy. 

 Having carefully compared it with Mr. Lea's original Troosti- 

 ana.^ I am led to believe them identical. In this case Mr. 

 Lea's name alone will stand, as that of Mr. Say is pre-occu- 

 pied." He adds, that of twenty-five specimens found in Ten- 

 nessee by Bishop Elliott, " all were w^ell marked H. Troosti- 

 aniaP Since our recent discussion of this subject, and further 

 careful study of the specimens referred to, Mr. Binney 



