396 / ECHINODERMATA. FISTULIDES. 



system is indistinctly traced ; and their organs of motion are 

 extremely imperfect. 



The Echinodermata are all marine animals, and have the fa- 

 culty, like many other of the more imperfect animals, of speedily 

 regenerating parts of their bodies which have been broken or se- 

 parated. Lamarck divides the class into three sections, viz. 

 FISTULIDES, ECHINIDES, and STELLERIDES, while Cuvier ar- 

 ranges it in two orders, the first including those which possess 

 numerous membranous tentacula, serving as organs of motion, 

 and the second those which are destitute of these organs. La- 

 treille makes two classes of the same animals, under the names 

 of Holothurida and Echmoderma. The arrangement of La- 

 marck is chiefly followed ; but we have added a fourth section, 

 comprising, under the title of CRINOID^E, given to them by Mr 

 Miller, the animal remains known by the name of Encrinites, &c. 



SECTION I. FISTULIDES. 



Skin soft, mobile, and irritable ; body elongated, cylindrical, 

 soft, and very contractile. 



The Fistulides have an elongated cylindrical body, strongly contractile, with the 

 internal organs distinct, and in a common cavity, and respire through the medium of 

 water by pores or retractile tubes. All live in the sea, near the coasts. 



Gen. 1. SIPUNCULUS, Lam. 



Body elongated, cylindrical, naked, narrowed posteriorly, but 

 with a terminal inflation, and having anteriorly a narrow cy- 

 lindrical neck ; mouth orbicular, terminating the neck, with a 

 cylindrical proboscis, finely papillated exteriorly and retrac- 

 tile ; anus lateral, placed towards the anterior extremity. 



S. nudus, Lam. With the epidermis striated. Inhabits European 

 coasts. Lam. iii. 78. 



S. edulis, Lam. Whitish flesh-coloured, cylindrical, subequal ; the 

 posterior extremity subclavate, the anterior dilated, papillose. 

 Inhabits Indian shores. Lam. iii. 79. 



Gen. 2. PKIAPULCJS, Lam. Holothuria, Lin. 



Body elongated, cylindrical, naked, annulated transversely, with 

 the anterior extremity glandiform, almost club-shaped, striat- 

 ed longitudinally, and retractile ; mouth terminal, orbicular, 

 with connate teeth at the orifice ; anus at the posterior extre- 

 mity, and a papilliform filament near it. 



P. caudatus, Lam. Three to six inches long. Inhabits shores of 

 the Northern Ocean. Lam. iii. 77- 



Gen. 3. FISTULAJUA, Lam. Holothuria, Mull. 



Body free, cylindrical, soft ; skin coriaceous, very rough and 



