SEA-CUCOJBERS. 157 



to the more favourable inclination of the sunbeams at this 

 early hour/^ 



Sea-Cucumbees. — (Plate X.) 



Sea-Cucumbers, or Holothuriadce, form an order of the 

 class EcJdmdermata, approaching, in some characteristics^ 

 the AcLiniadm, through such genera as Peachia and Ed- 

 wardsia; and, on the other hand, the Star-fishes and Echini. 

 To the latter they more properly belong. In short,, Pro- 

 fessor Porbes considers a Sea-Cucumber in the light of a 

 soft Echinus and long-bodied Star-fish combined. 



True Starfishes J Echini, and Holothuriadce, all possess 

 and use, as one means of progression, rows of movable fila- 

 ments, which are contractile, and have at their tips httle 

 sucker-discs. In the latter, to which class our Pentacta, 

 or Cucumaria, belongs, these suckers are arranged in five 

 rows along the body, dividing it into five sides. The skin 

 of these animals is soft and leathery. In some species 

 the suckers are more developed on the under side, so 

 as to form a creeping surface, in opposition to the upper 

 or dorsal surface. But, as a rule, the animals crawl in- 

 differently on any side. Suckers are not, however, the only 

 means of locomotion possessed by the Kolothuriadce ; for 



