REPORT ON THE HOLOTHURIOIDEA. 169 



Lcetmogone wyville-thomsoni, Thud. 

 Fig. 4. Side view of the anterior portion of the body, with the left side removed to 

 show the position of the inner organs, a, madreporic canal ; b, papillae in 

 connection with the madreporic canal ; c, genital process ; d, efferent duct 

 of the reproductive organs ; e, pseudhaemal vessels ; f, calcareous ring ; g, 

 reproductive organs ; h, Polian vesicle ; i, water-vascular ring ; k, main 

 canals combining the water-vascular ring with the tentacles and the radial 

 ambulacral vessels ; m, radial ambulacral vessels ; t, tentacles ; x, the 

 foremost portion of the perisoma of the left side turned forwards. 



Deima fastosum, Theel. 

 „ 5. A part of the system of canals which surround the foremost portion of the 

 alimentary canal and are in connection with the small papillae which are 

 presented in figure 2 of this plate, a, papillae ; b, part of the disk-like 

 perisoma which surrounds the anterior aperture of the body ; c, the blind 

 ends of the canals cut off ; d, canals ; e, nerves. 



Oneirophanta mutabilis, Theel. 



,, 6. Side view of the anterior portion of the body with the left side removed to 

 show the inner organs, a, madreporic canal ; b, efferent duct of the 

 reproductive organs ; c, pseudhsemal vessel passing to the reproductive 

 organs ; d, male reproductive organs ; e, mesentery ; f, dorsal pseudhasmal 

 vessel ; g, intestine ; h, Polian vesicle ; i, ventral pseudhsemal vessel ; k, 

 elastic bands and threads ; I, circular pseudhsemal vessel ; m, water- 

 vascular ring ; n, radial ambulacral vessels ; o, minute apertures visible 

 through the thin walls of the water-vascular system, by which apertures 

 the five main canals communicate with the tentacles and the radial 

 ambulacral vessels ; p, opening formed by the medio-dorsal mesentery ; r, 

 main canals. Natural size. 



Deima vcdidum, Theel. 



,, 7. View of the termination of the odd ventral main canal into the tentacles and 

 odd radial ambulacral vessel, a, a portion of the odd main canal ; b, 

 calcareous ring ; c, branches of the main canal passing to the tentacles ; 

 m, tentacular cavities ; n, nerve ring; o, tentacular nerves; k, the same 

 minute canals which are represented in the figures 2 and 5 of this plate ; 

 x, odd radial ambulacral vessel ; y, branch of the main canal which 

 passes into the odd radial ambulacral vessel ; z, ventral body-wall. The 

 tentacles as well as the ends of the fine canals are removed. 



(ZOOL. CHALL. EXP. — PART XIII. 1881.) N 22 



