44 



j. F. MCCLENDON. 



om 



- 



ec 



ol 



FIG. 4. Fourth stage of same, X 45- ec, anterior margin of ectoderm growing over 

 the first neuromere ; tb 1 , first lung book ; MX, maxillaria ; en, oesophagus; al, latera- 

 eye ; om, median eye sac; si, semilunar lobe. 



FIG. 5. Fifth stage of same, X 45- a i anus; ab 1 2 , first and second abdominal 

 appendages ; ec, anterior border of ectoderm growing over first neuromere ; lb' first, 

 lung book ; ol, lateral eye ; si, semilunar lobe ; 4/4, anterior nerve of the fourth 

 neuromere \P, posterior nerve of fourth neuromere. 



