336 Puget Sound Marine Sta. Pub. Vol. 1, No. 28 



PLATE 76 



o«=:auditory sac 

 6Z^blastopore 

 hn=nuclei of blastoderm 

 ^r=gerin ring 

 m*=mesodermal somites 

 /j=periblast 

 «cm=secondary caudal mass 



Fig. 19. Surface view of 10-day egg from side; advancing germ 



ring; embryo. X 7.6. 



Fig. 20. Surface view of 11 -day egg from side; advancing germ 



ring; embryo. X 7.6. 



Fig. 21. Surface view of 12-day egg from side; embryo; yolk blasto- 

 pore. X 7.6. 



Fig. 22. Surface view of 13-day egg; embryo complete; blastoderm 

 covering entire yolk. X 7.6. 



Fig. 23. Section thru 6-hour disk; 2-celled stage. X 43.8. 



