54 INTUODUCTION TO ZOOLOGY. 



ones m large holes ; and. their purple spines and regular forms 

 presented a most beautiful appearance studding the bottoms 

 of the gray limestone rock-pools." 



The individuals of the fifth family (Holothuridce) ari3 not 

 likely to attract the notice of the casual observer, and are of 

 comparatively rare occun-ence even to the naturalist. The 

 English tenn, Sea-cucumbers (Fig. 35), gives some idea of 

 their general form. In them the spines have disappeared; 

 but, as the covering of the body is soft, they can move by the 



extension or contraction of its parts, as worms do; and, like 

 the Sea-urchins, they continue to employ the aid of suckers. 

 They are remarkable for their power of casting off and of 

 reproducing parts that would seem the most essential. Sir 

 J. G. Dalyell* has known them to lose "the tentacula, with 

 the cylinder (dental apparatus), mouth, oesophagus, lower 

 intestinal parts, and the ovarium, separating fi'om within, and 

 iea-ving the body an empty sac behind. Yet in three or four 

 months, all the lost parts are regenerated." 



Mr. Forbes states, — " It is this animal which the Malays 

 of the Oriental Isles seek so diligently for the supply of the 

 China market, where it obtains a good price when well pre- 

 served. It is employed by the Chinese in the preparation of 

 nutritious soups, in common with an esculent sea-weed. Sharks' 

 fins, edible birds' nests, and otheV materials, affording much 

 jelly. Jaeger says the intestines are extracted, the animal 

 then boiled in sea-water, and dried in smoke." 



A species found off the coast of CornM'all, and first described 



• Paper read at Glasgow Jleeting (1840) of British Association. 



