I 



BY H. L. KESTKVEN. 687 



EXPLANATION OF PLATES LXVIH.-LXX. 

 Plate Ixviii. 



Fig. 1. — Diagrammatic representation of the arrangement of the internal 

 organs : a, mouth — h, ovary — c, uterus — d, receptaculum 8eminis(?) 

 — e, oviduct—/, vulva — <j, slime-gland — li, solid posterior end of gut. 



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

 • c, endoskeletal rod of chitin— d, antennule- e, antenna—/, mandible 

 —g, A— legs. 



Fig.3. — Posterior third of a female specimen : a, viilva — 6, genital append- 

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



Fig. 4. — Outline of a male specimen. 



Fig. 5. — Antenuule. 



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 endomesoderm anlagen 

 during gastrulation(c/ Fig. 39). 



Plate Ixix. 



Fig. 15. — Transverse section at the level of the oral cavity : ce, resophagus 



— cav., oral cavity. 

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



tirst compartment. 

 Fig. 17. — A subdermal gland. 



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

 Fig. 19. — Kpithelium of the anterior portion of the tirst compartment. 

 Fi<'.20.— Transverse section at the level of the ovaries: Or. , ovary — id., 



uterus. 

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



compartment. 

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



^^., digestive(?) gland. 

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



oviduct(oi;d. ). 

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



commencement of the oviduct{oz;d. ). 



64 



