DOO 



Maldanid.e.- 



-ANNELIDA.- 



-SUCTORIA. 



Family IV.— MALDANID^. 



Tliis family contains only one genus, Clymene, and 

 this genus possesses as yet only one species. This is 

 a very curious worm, destitute of brancliife and tentacles, 

 and living in a fi.\ed tube of a membranous substance, 

 but incrusted with shells, and open at both the e.\- 

 tremilies. The tube is bard, compact, irregular, 

 constructed of sandy particles, united by an exudation 

 apparently from the whole body, and fashioned chiefly 

 during the night. 



OnDEU III.— TERRTCOLA (Abranclna scligcra) 

 Earthworms. 



The animals belonging to this order have all a very 

 simple organization. The body is truly vermiform, 

 cylindrical, composed of numerous uniform but narrow 

 segments, which possess no soft appendages or cirrhi, 

 but are furnished with spines, or spinets, or setaceous 

 bristles partially retractile. These bristles are almost 

 never grouped in bundles, but are arranged iu ]>airs 

 near each other, and upon the sides of the segments. 

 There is no distinct head, and neither eyes norantennie 

 are visible. The mouth is destitute of jaws, and there 

 are no feet ; the bristles or spines on the sides of the 

 rings taking their place. No external organs of respira- 

 tion exist; the vent opens underneath the last segment. 

 As their name indicates, the worms of this order live 

 in moist earth, or in mud saturated with water, which 

 they swallow, and from which they extract their food. 

 They unite both sexes in the same individual, and are 

 oviparous or multiplied by spontaneous division. The 

 young undergo no metamorphosis. The animals pos- 

 sess the power of reproducing portions of their body 

 which have been amputated, and they may even be 

 divided into several portions without destruction to life. 

 Several species have been observed to excrete a phos- 

 ithorescent fluid, and the skin of others is iridescent. 



Family I.— LUMBRICID^ (Earthworms). 



The animals of this family are distinguished by the 

 head being indistinct, and all the segments of the body 

 excepting the first being armed with setae. The mouth 

 is never furnished with tentacles, but is edged by two 

 lips. The bristles which supply the place of feet are 

 distributed over all the segments, and only rarely form 

 fascicles. They are non-retractile, and never have 

 the form of hooked bristles. The Common Earth- 

 worm {Lumhricus terrestris) is the type of the family, 

 and is too well known to require description. 



Family II.— NAID^ {The Naides). 



In this family the head is distinct from the body, 

 and tlie first three or four segments are without bristles. 

 The mouth is exactly terminal, whilst in the preceding 



family it is situate underneath a superior terminal 

 lip. The Naides are small, pellucid, vivacious worms, 

 difiering from the Earthworms by the flatness of their 

 segments, which are furnished with comparatively long 

 setaceous bristles. They are all strictly lacustrine, 

 living amidst subaquatic plants, or, half parasitical, 

 within the shell of fresh-water Mollusca. They creep 

 about actively, and can even swim. The segments of 

 which the body is composed are less distinct than those 

 of the Lmnbrici, though the body is more elongate. 

 The number of bristles wdiich each segment is armed 

 with, varies from two to ten, or twelve. They are of 

 two kinds — spinets forked at the apex, and setaceous 

 collected in small fascicles. The animals are zoopha- 

 gous, and though most probably oviparous, they mul- 

 tiply easily by spontaneous division. This fact has 

 been particularly noticed by British naturalists in the 

 case of Nais {Siylaria') p}-ohoscidea, a small, linear, 

 round worm, about half an inch long, that is common 

 about the roots of aquatic plants in our ponds and 

 ditches. When this process commences, says Mr. Lewis, 

 who has watched the operation, the little worm begins 

 to form a second head near the extremity of its body. 

 After this head, other segments are in turn developed, 

 the tail or final segment being the identical tail of the 

 mother, but pushed forward b}' the young segments 

 and now belonging to the child, and only vicariously to 

 the mother. In this state, he adds, we have two worms 

 and one tail. 



Order IV.— SUCTORIA (= Ahranchia Non- 

 sctiijera) Leeches. 



This is a natural order of worms and more clearly 

 defined and circumscribed than any of the preceding. 

 The body is elongated, depressed in general, and divided 

 into a great number of narrow segments — the anterior 

 conformed into a more or less distinct sucker with the 

 mouth in its centre or on its ventral side; the posterior 

 forming a terminal, circular, cupped disc. The month 

 possesses organs performing the functions of jaws, but 

 usually has neither proboscis nor tentacles. On the 

 dorsal face of the anterior rings there are in general 

 several (from two to ten) small black points which are 

 considered to be eyes, and are arranged in pairs. In 

 most cases there are no special respiratory organs 

 visible externally ; and though there are no organs of 

 taste, smell, or hearing, the sense of touch is exquisite 

 and difl'used. The animals belonging to this order, as 

 the name indicates, are all more or less parasitical and 

 aquatic. A few are zoophagous, devouring small niol- 

 lusks, larvae of insects, &c.; but by far tlie greater num- 

 ber suck the juices of other animals, as fishes, frogs, or 

 animals which happen to go into the water in which 

 they reside, lodging themselves occasionally in their 

 palate, under the tongue, nasal fossa.', or even the 

 oeso]ihagus. Savigny informs us that during the French 

 expedition to Egypt, they at times caused serious iicci- 

 denls to soldiers wdio drank at the fountains iu which 

 these creatures lived. When cold weather commences 

 they bury themselves in the mud of ponds, and there 

 pass the winter in a state of lethargy, from which they 



