-464! PBOF. A. DENDX ON CAUDIKA COETACEA. 



DESOEIPTION OF PLATE 29. 



Oaudina coriacea, Hutton. 



Fig. 1, Posterior extremity of a very young specimen Tiewed as an opaque 

 object, showing the anus surrounded by the five groups of "anal 

 papilla." (From a " tail "-fragment dredged in Lyttelton Harbour.) 

 X30. 



Fig. 2. Group of anal tentacles of an older but still young specimen, viewed as 

 a transparent object. Zeiss D. Oc. 1. 

 (Figs. 3-12. Transverse sections of the " tail " of fig. 1, numbered from 

 the posterior extremity forwards.) 



Fig. 3. The 80th section. Zeiss A. Oc. 1. 



Fig. 4. The 18th section. Zeiss A. Oc. 1. 



Fig. 5. The 8th section. Zeiss A. Oc. 1. 



Fig. 6. The 3rd section. Zeiss A. Oc. 1. (Reversed as compared with fig. 1.) 



Fig. 7. Eadial portion of the 79th section. Zeiss D. Oc. 1. 



Fig. 8. Eadial portion of the 18th section. Zeiss D. Oc. 1. 



Fig. 9. Eadial portion of the 13th section. Zeiss F. Oc. 1. 



Fig. 10. Eadial portion of the 10th section. Zeiss D. Oc. 1, 



Fig. 11. Eadial portion of the 8th section. Zeiss D. Oc. 1. 



Fig. 12. Eadial portion of the 3rd section, showing only a group of anal 

 tentacles and a vestigial anal tooth. Zeiss D. Oc. 1. 



Fig. 13. Entire young specimen from New Brighton Beach. Natural size. 



Reference Letters. 



Jimp. Ampullary dilatations of the branches of the radial ambulacral vessels 

 (circumanal ampullae). 



c.c. Ccelomic canals partially surrounding the longitudinal muscles. 



cl. Cloaca. 



cm. Circular muscles. 



.Corp. Corpuscles. 



ep. Epineural canal. 



.hyp. Hyponeural (pseudohsemal) canal. 



i.b. Inner baud of radial nerve. 



m.f. Muscle-fibres cut across. 



o.b. Outer band of radial nerve. 



r.a. Eadial ambulacral vessel. 



r.m. Eadial longitudinal muscle. 



r.n. Eadial nerve. 



r.s. Eadial blood-sinus. 



sp. Spicules. 



t. Supposed vestigial anal teeth. 



t.a. Ambulacral vessel of anal tentacle. 



ten. Anal tentacle. 



t.m. Transverse muscles. 



t.n. Nerve of anal tentacle. 



3'ofe. — The sections were cut from a specimen treated with borax-carmine and 

 acid alcohol, and the spicules are therefore not shown. 



