REPORT ON THE HOLOTHURIOIDEA. 165 



natural size, a, water-vascular ring ; b, Polian vesicle ; c, circular pseud- 

 hsemal vessel ; d, ventral pseudhsemal stem ; e, the long commissural vessel ; 

 f, the short commissural vessel ; x, anal termination of the digestive tract. 

 Fig. 3. Posterior portion of the digestive tract opened, a, cloacal dilatation ; b, anal 

 portion of the digestive tract which is capable of being retracted within 

 the body as well as extended beyond it ; c, space enclosed by the double 

 walls of the anal portion of the digestive tract ; d, that part of the 

 perisoma which surrounds the anus ; x, muscular threads. 



Benthodytes sanguinolenta, n. sp. 



„ 4. A portion of the intestine ; twice the natural size, a, intestine ; b, diverti- 

 culum. 



„ 5. Ventral view of the anterior part of the alimentary canal, a, water-vascular 

 ring ; b, ventral pseudhsemal vessel ; c, oral portion of the digestive tract, 

 visible through the mesentery which surrounds it ; d, intestine ; e dilatation 

 of the intestine ; m, mesentery ; o, the main canals which proceed from 

 the water- vascular ring ; p, Polian vesicle. 



Benthodytes sanguinolenta, var. marginata, n. 

 „ 6. Transverse section of the body ; twice the natural size. A, dorsal surface ; 

 B, ventral surface ; D, peritoneal cavity ; a, processes of the dorsal 

 ambulacra ; b, pedicels of the odd ambulacrum ; c, pedicels of the ventral 

 lateral ambulacra ; m, ventral ambulacra ; n, dorsal ambulacra. 



Euphronides depressa, n. sp. 



„ 7. View of a part of the inner side of the odd interambulacrum ; twice the natural 

 size, a, dorsal ambulacra ; b, ambulacral cavities communicating with the 

 two canals which penetrate the azygous appendage ; x, the connection of 

 the cavities with the dorsal ambulacra. 



Benthodytes sanguinolenta, var. marginata, n. 

 ,, 8. Diagrammatic outlines of the lateral pedicels ; twice the natural size, a, one 

 of the lateral ambulacra ; b, cylindrical cavities which enter the pedicels ; 

 c, pedicels ; d, communication between the ambulacrum and the pedal 

 cavities. 



PLATE XLI. 



Oneirophanta mutabilis, Theel. 

 Fig. 1. Upper view of a piece of the dorsal perisoma deprived of the outer layer of 

 connective tissue which contains the calcareous deposits, a, longitudinal 

 muscular band ; b, transverse muscular layer ; c, large branched ambula- 



