EXPIANATION OF PLATE XXVII. 



Fig. 2. — Specimen No. 2. Transverse section through the 

 mouth. X 100. 



Fig. 3. — Transverse section through the first pharynx X 100. 



Fig. 4. — Transverse section through the first pharynx and 

 dorsal ganglion. X 100. (1/2/f.) 



Fig. 5. — Transverse section through the second pharynx and 

 lateral nerve commissure. X 100. (1/3/i ) 



Fig. 6. — Transverse section through the posterior portion of 

 the second pharynx and ventral nerve commissure. X 68f . (i/3/|- ) 



