Fig. 1. Plan of the central nervous syscern of Coliirostyliis . XIO. 



Fig. 2 and Fig. 3. Cross sections of tlie brain, one half shown. X150. 



Fig. 4. Cross section of the first ventral ganglion. XI 5n. 



Fig. 5. Cross section of one of the thoracic ganglia. XI 50. 



Fig. 6. Cross section of one of the upper alnlominal ganglia. XI 50. 



Fig. 7. Surface view of one of tiie thoracic ganglia. XI 50. 



Fig. 8. Surface view of an upper ahcloininal ganglion. X150. 



Fig. 9. Surface view of the last alnlominal ganglion. .\150. 



