210 Messrs. E. A. Smith and B. B. Woodward on 



They have been extensively relied on by specialists in 

 formulating subdivisions of the genus, and hence a definite 

 and correct nomenclature becomes of the highest importance 

 to the student. 



On this account, and in hopes of reducing to order the con- 

 fusion which has arisen through the various applications of 

 some of the terms, these notes have been put together and the 

 accompanying explanatory table with the figures prepared. 



Most of the available published descriptions are, unfortu- 

 nately, either like those of A. Schmidt, unaccompanied by 

 the figures so indispensable to their right understanding, or, 

 where figures are given, as in Fischer's Manual, both are 

 inadequate, since folds shown in the cuts are neither lettered 

 nor described ; indeed, we are free to confess that without an 

 appeal to Caesar certain points would still have remained 

 doubtful in our minds. 



Dr. Bottger, from whom aid was naturally sought in a 

 question affecting a subject of which he is so perfect a master, 

 not only most kindly afforded in writing the information 

 desired, but also took the trouble to prepare and send over 

 marked specimens *, so that no doubt now remains respecting 

 the correct identification of Schmidt's nomenclature. 



For many reasons it seems best to employ the Latin terms 

 which have been applied to these folds or plaits. Moreover, 

 since the German specialists have carried the study in con- 

 nexion with them furthest and have framed the most com- 

 plete system of nomenclature, it appears most advisable to 

 adopt Dr. Bottger's modification of Schmidt's terminology. 



In the accompanying table (facing this page), to save space, 

 these Latin terms are placed together in the first column, 

 lettered to correspond with the figures, and not- repeated, 

 where the vernacular equivalents occur, in the following ones. 

 By referring to this table and the illustrations the significa- 

 tion of any term employed by the authors quoted can be seen 

 at a glance. 



Perhaps it may not be out of place here to briefly sketch 

 the history and development of this system of nomenclature. 



Rossmiissler appears to have initiated it. In 18o5| he desig- 

 nated the two principal folds on the columellar lip as the 

 lamella superior and lamella inferior, and named the interla- 

 mellare between them. A little later (1836) J he distinguished 



* Now in the Natural-History Collection of the British Museum. 

 t Iconog. pt. i. p. 75. 

 X Op. cit. pt. iii. p. 8. 



