FIG. 270. Stage J. Section not quite median. Lettering as before. In addition : cts, cephalo- 

 thoracic shield ; ms, mesoderm segments ; tgi, 1st thoracic ganglion (of 1st maxillipede) ; mg, 

 inandibular ganglion. 



mm. 



lfUJ- 



Dm 



Fig. 2SO. Ripe embryo. Lettering as before, mu, Mouth ; Lm, ventral chord ; wise, muscu- 

 lature ; aa, arteria abdominalis ; as, arteria sternalis ; Id, diverticula of the mid-gut (hepatopancreas) 

 li, heart; pc, pericardium ; md, extensions of the mid-gut ; mm, muscles of the masticatory stomach ; 

 pk, pyloric valve. 



