KXPT.AXATTON OF TT-ATES 1-9. 99 



Plate 3. 



F'igs. 1-7, 9-1 1. C. bocki; Fig. 8. C. willeyi. 



Figs. 1-7. Sections of body of adult parallel with the sagittal plane; the planes of 

 sections are shown in Pi. i, Fig. 2 (.\-A : Fig. i, BB : Fig. 2. CC : Fig. 3, D-D : Fig. 4, 

 E-E : Fig. 5, F-F : Fig. 6, (1-G : Fig. 7); x 60 



Fig. 8. Submedian transverse section of body of adult; only the median part of the 

 left half are .shown; x 60. 



Figs. 9-1 1. .Sections of larva of the stage directly after hatching, parallel with the 

 sagittal plane; the planes of sections are shown in PL 7, I'isr. 20 (.'V-A : I'ig. 9, B-B : Fig. 10, 

 C-C : Fig. 11); X300. 



Plate 4. 



Figs I, 2, 17. C. mitsukurii\ Figs. 3-9, 16 e-i. C. bocki; Figs. 10-15, 16 ad. C. 

 willeyi. 



Fig. I. Dorsal epidermis; X 1000. 



2. Ventral epidermis; X 1000. 



3. The same; X 1000. 



4. Dorsal epidermis; surface view of a fresh material; X420. 



5. Ventral epiderjriis; surface view of a fresh material; X420. 



6. Aboral region of a .specimen observed alive, view from surface, with the 

 entrance into tlie sensory cavity openned; Xl7o- 



7. Parts adjoining polar plates of a specimen observed alive, side view, with 

 the aboral lobate prominences kept erect; X170. 



8. Semi-diagrammatic figure showing the sagittal section of central part of 

 body adjoining aboral sense-organ; X300. 



9. Otolithic granules; X 700. 



10. Cross-section of the core of accessory filament; X550. 



11. Median longitudinal section of the same; X550. 



12. Successive developmental stages of colloblast; x 1400. 



13. Cross-section of oesophagus; X150. 



14. Horizontal section of the region adjoining pr)lar plates and excretory canals; 

 X150. 



15. Section of the region including a branch of anastomosing canal-system; 

 X400. 



16. Corpuscles in gastro- vascular canal; ad. fixed and stained material; xgco; 

 g-i. fresh material; X420. 



17. Ciliated rosette; X 1400. 



Plate 5. 



Figs. I, 4, 6, 7, 12. C. bocki; Figs. 2, 5, 9-1 1, 13, 14. C. willeyi; Figs. 3, 8. C. 

 mitsukurii. 



Fig. I. Testis and ovary, X150. 



2. Testis and very immature ovary; x 1 50. 



3. Spermatozoa; X1600. 



