IX 



PHYLUM ECHINODERMATA 



355 



lie numerous large cells, some of which are pigmented, and the 

 walls of the spaces are lined with an epithelium of flattened cells. 

 At its dorsal extremity the organ terminates in a narrow pro- 

 longation with a single central canal, which ends in a ring-like 

 canal surrounding the anus ; this gives off five radial branches 

 which pass to the reproductive organs. Surrounding the body .of 



fit/I . ccco 



jbci. 



FIG. 2s:5. Anthenea flavescens. Dorsal view of a dissection of the internal organs. The 

 dorsal wall of the body, with the exception of a small portion round the anus and the madre- 

 porite, has been completely removed. One of the five intestinal caea has been removed with 

 the exception of its proximal part. All the ovaries have been removed except one pair, and 

 four of the pairs of pyloric cueca have been cut away close to their bases. 1 5, the five rays 

 with their ambulacral ridges; aiu/>. ampulhe ; nil. anus; int. cur. intestinal cseca ; /. p. cut 

 ends of the inter-radial partitions ; until, madreporite with the madreporic canal ; or. ovaries ; 

 ,ail. ses. Polian vesicles; pi/I. <-nc. pyloric cajca ; nti: retractor muscles inserted into the 

 cardiac division of the stomach. 



the gland is a blood-sinus the n.'-'ml sinus connected orally with 

 the oral ring blood-vessel ; and connected with this at its aboral 

 end is a ring-like vessel enclosing the ring-like canal in continuity 

 with the ovoid gland, and giving off prolongations to the repro- 

 ductive organs. The cavity of the ovoid gland communicates by 

 a minute aperture with the madreporic canal, and thus, indirectly. 

 with the exterior. 



A A 2 



