BY H. L. KESTKVEN. 687 



EXPLANATION OF PLATES LXVIIL-LXX. 



Plate Ixviii. 



Fig.L — Diagriimmatic representation uf the arrangeiiieiil of the internal 

 organs : ft, mouth — b, ovary — c, uterus — d, receptaculuni seniinis(?) 

 — e, oviduct—/, vulva — rj, slime-gland — h, solid posterior end of gut. 



Fig.2. — Anterior third of a female specimen: a, mouth — h, cesophagus — 

 c, endoskeletal rod of chitin— rf, autemiule- e, antenna—/, mandible 

 — Sr, /i- legs. 



Fig. 3. — Posterior third of a female specimen : u, vulva — />, genital append- 

 ages — c, slime-glands — d, posterior end of gut. 



Fig. 4. — Outline of a male specimen. 



Fig. 5. — Antennule. 



Fig.6. — Antenna. 



Fig.7. — Mandible. 



Fig. 8.— First leg. 



Fig.9. — Antenna or mandible, from an embryo about the same stage of 

 development as that represented in Fig. 43. 



Fig. 10. — The two-celled embryo. 



Fig. 11. — The four-celled embryo. 



Fig. 12. — The sixteen-celled embryo. 



Fig.13.— The gastrula. 



Fig. 14. — Showing evidence of rapid division of the endomesodeim anlagen 

 during gastrulation(c/ Fig. 39). 



Plate Ixix. 



Fig. 15. — Transverse section at the level of the oral cavity : c, ifHophagns 



— cav., oral cavity. 

 Fig. 16. —Longitudinal section in the region of junction of cesophagus and 



first compartment. 

 Fig. 17. — A subdermal gland. 



Fig. 18.— Transverse section just in front of the ovaries. 

 Fig. 19. — Epithelium of the anterior portion of the drat compartment. 

 Fig. 20. — Transverse section at the level of the ovaries : Of., ovary --it^, 



uterus. 

 Fig.21. — Transverse section at the level o^ the posterior end of the fiist 



compartment. 

 Fig. 22. — Transverse section at the level of the second compartment: 



fjL, digestive(?) gland. 

 Fig.23. — Transverse section at the level of the junction of uterus and 



oviduct(ofd. ). 

 Fig. 24. — Transverse section at the level of the posterior end of uterus and 



commencement of the oviduct(o»d. ). 

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