CHEMNITZIA. 447 



at one time I thought it a variety of that species, but the 

 different disposition of the spiral striae, the more oblique ribs 

 and hollowed-out volutions in the C. excavata, show that the 

 C. Barleei is distinct, though most closely allied to it. The 

 apex of C. excavata is reflexed precisely as in this species. 

 This character with me, as regards the Ckemnitzics, is of great 

 value ; in that tribe the decidedly reflexed apex, or the sunken 

 subreflexed one, I never found absent. But the examples 

 must be fresh and perfect not the usual cabinet ones ground 

 to button-like apices by attrition; but even in these the 

 practised eye will detect the true character. The fold on the 

 pillar-lip of the C. excavata is sometimes present, and at 

 others absent. I believe this remark holds good in this spe- 

 cies; but in my specimens from Mr. Barlee it is distinctly 

 visible, though very small, and far retired within the aperture. 



CH. NITIDISSIMA,' Mont, et Auct. 

 Aclis nitidissima, Brit. Moll. iii. p. 223, pi. 90. f. 6, 7- 



Though the animal of this elegant minute shell remains 

 undiscovered, still the inversion of its apical turns on the 

 succeeding volution is so excellent and faithful a characteristic 

 of the Chemnitzia (of which I am not aware of an instance of 

 failure), that I am induced, without hesitation, to consider 

 this species as a member of that genus, and I confidently 

 expect that, when the animal is deterre, it will support me in 

 the step I have taken. This character, which I think of great 

 value as a conchological aid, is far preferable to the unstable 

 columellar fold. 



CH. EXCAVATA, Philippi. 

 Odostomia excavata, Brit. Moll. iii. p. 305, pi. 97. f. 3, 4. 



This species has not been met with alive, though the shell, 

 in excellent condition, has been taken at Exmouth. 



CH. SCILL^E, Scacchi. 



Eulimella Stilla, Brit. Moll. iii. p. 309, pi. 98. f. 5, 6 ; (animal) 

 pi. F.F. f. 7. 



This species does not inhabit the Devonshire coasts. 



