448 



We Ihall however take this opportunity to remark, 

 that great attention is requifite in the inveftigation of 

 thefe microfcopic fpecies, which we fear have already 

 been unneceflarily multiplied, arifing from the difficulty 

 of defcribing and delineating fuch fmall objefts under a 

 microfcope. Thofe who have been in the habits of 

 ftudying the diminutive works of nature in this way, are 

 aware of the difficulty. Much caution is alfo requifite in 

 admitting thofe minute fpecies of ffiells, with only two 

 or three volutions as diftinft, unlefs they pofTefs fome 

 charafter which ftrongly marks them as fuch, as many 

 are probably the fry or young of others. Upon this 

 principle we have rejefted many which have come under 

 our infpeftion, rather than puzzle fcience with uncer- 

 tainty. 



^**DEPRESSED, APEX COMPRESSED. 



59. 

 Cornea. Helix cornea. Lin. Syft. p. 1243. — Gmel. Syji. p. 3623. 35. 



Lifter Conch, t. 137.f.41 Id. AngJ. t.2.f.26. 



C/iem. Conch, ix. t. 127. f. 1 1 13. 1 1 15. 

 Schroet FinJJconch. t.5. f. 19. 20. 21.— & t.M/z. 



C. f. 7.— G«ci//. t. 4. D. D. 

 Mulkr Verm. ii. p. 154. No. 343. 

 Vetiv. Gaz. t. 92. f. 5.— Br. Zool. t. 83. f. 126. 

 Favan. Zoovwrph. t. 75. D. 1.2. 3. 

 Pult. Cat. Dorfet. p. 47. 

 Hill. Swammerd. p. 83. t. 10. f. 3. 



Helix 



