FIG. 279. 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, 

 mandibular ganglion. 



nut 



Fig. 280. Eipe embryo. Lettering as before, mu, Mouth ; 6w, ventral chord ; msc, muscu- 

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

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

 pk, pyloric valve. 



