HOLOTHURIANS OF KEW ZEALAND. 51 



Fig. 3 a. Optical vertical section of slightly later stage, with the thickening 

 greatly increased. 

 Figs. 4-5. Later stages ; the thickenings have met together so as to enclose a 

 hexagonal aperture. (Zeiss D, Oc. 2, Camera.) 

 (In figs. 3, 4, 5 the primary six-rayed cross is shaded and the spicule 

 is represented as transparent.) 

 Fig. 6. Later stage, represented as an opaque object and showing the 

 commencement of the rim of the wheel. (Zeiss D, Oc. 2, 

 Camera.) 



7. Sigma-shaped spicules. (Zeiss D, Oc. 2, Camera.) 



8. Part of calcareous ring, X 12. 



Figs. 9-18. Caiidina coricwea. 

 Figs. 9-11. Characteristic spicules of the integument. (Zeiss D, Oc. 2, Camera.) 

 12-14. Irregular spicules from tip of tail. (Zeiss D, Oc. 2, Camera.) 

 Fig. 15. Coloured corpuscles of the coelomic fluid. (Zeiss D, Oc. 3.) 



15 a. Group of similar corpuscles, polygonal from mutual pressure. 

 (Zeiss D, Oc. 3.) 



16. Large, coarsely granular, colourless corpuscle from the coelomic 



fluid. (Zeiss D, Oc. 3.) 



17. Small, finely granular, colourless corpuscles from the coelomic 



fluid. (Zeiss D, Oc. 3.) 



18. Part of calcareous ring, X 3. (A few transverse cracks, appar- 



ently accidental, have been omitted.) 



Figs. 19, 20. Cucumaria Huttoni. 



Fig, 19. Pharynx, showing calcareous ring, &c., X 2. i., interradial 

 plate ; r., radial plate ; r.ni., retractor muscles ; m.c, madreporic 

 canal ; p.v., Polian vesicles ; a.c, alimentary canal. 

 20. Small reticulate plate from integument. (Zeiss D, Oc. 2, Camera.) 



Plate 4. 

 Figs. 21-32. Colochirus alba. (Specimen from the Wellington Museum.) 

 Figs. 21-24. Small reticulate plates from integument. (Zeiss D, Oc. 2, Camera.) 

 25-26. Perforated rods. (Zeiss D, Oc. 2, Camera.) 

 27-31. Reticulate cups from different points of view. (Zeiss D, Oc. 2, 

 Camera.) 

 Fig. 32. Part of calcareous ring, X 13. 



Figs. 33-43. Colochirus ocnoides. (Specimen from New Brighton.) 



Fig. 33. Dissection, showing pharynx, crown of tentacles, &c.,, X 3. i., 



interradial plate ; r.m., retractor muscles ; m.c, madreporic 



canal ; p.v., Polian vesicle ; a.c, alimentary canal ; g.d., upper 



end of genital duct ; int., integument around crown of tentacles. 



34. Part of calcareous ring, X 15. (The crack across the radial 



plate is probably accidental.) 



35. Part of large reticulate plate from integument. (Zeiss D, Oc. 2, 



Camera.) 



36. Small reticulate plate from integument. (Zeiss D, Oc. 2, Camera.) 



4* 



