170 Pub. Puget Sound Biol. Sta. Vol. 2, No. 44 



PLATE 23 



a.f, attachment filament. 



ch, chitinous exoskeleton. 



f.g, frontal gland. 



mx", second maxillae. 



mo'p, maxillipeds. 



oe, oesophagus. 



ph, pharynx. 



ph.g, glandular cells of pharynx. 



s.g, shell glands. 



w, body wall. 



Fig. 16. Transverse section of first copepodid larva in region of 



pharynx. X500. 

 Fig. 17. Transverse section of first copepodid larva showing shell 



glands (s.g). The oesophagus (oe) can be seen as a 



circular tube fully developed. X460. 



