INTRODUCTION 



For convenient reference a diagram showing the termin- 

 ology of the teeth is repeated here. 



Lamellae 



Sapracolumellar ~ 



COLUMBLLAR 



'""'jir Suprapalatal 



UPPER PALATAL 

 -* Inter palatal 

 ^ LOWER PALATAL 



I Iniracolumellar -....... 



V *\ ft ^7^ i 



~~z& Infrapalatal 



**^, BASAL 

 FIG. 1. TERMINOLOGY OF LAMELLAE AND FOLDS. 



The names of primary teeth are in small capitals. 



The bay formed by the upper arc of the outer lip, and 

 usually limited by the upper palatal and angular teeth, is 

 called the SINULUS. This term has also been used extensively 

 in Clausilia, Ennea, etc., in the same sense. 



In Vertigo, the point of the outer lip, running forward or 

 bent inward, has been termed the AURICLE by Dr. Sterki. 



The ridge encircling the whorl behind and parallel to the 

 free margins of the peristome is known as the CREST (collar, 

 calliis cervicalis, ~bourrelet exterieur, Nackenwulst) . 



(vii) 



