EXPLANATION OF THE FIGURES. 



All the figures from 1 to 20 and Fig. 26 are free hand 

 drawings made from the living specimens. Figs. 21 to 25 are 

 from well preserved specimens mounted in balsam and were out- 

 lined with the camera lucida. The remaining figures are cam- 

 era lucida drawings of microtome sections. 



Lettering common to all the Figures . 



- 72 



