Amphinomid-b.- 



-ANNELIDA.- 



-Nr.UEIDID.«. 



297 



most important characters. We give, as an illustration 

 of this family, a figure of Aplirodita lnjstrix, the 

 Porcupine Sea-mouse, a native of our own shores. — 

 See fig. 202. 



■. 202. 



Aplirodita hystrix. 



Family II.— AMPHINOJIID^ {The Amphinomes). 



The Amphinomes are distinguished from the .<4/jAro- 

 dilidw hy their generally elongated hody being always 

 destitute of elytra or scales. The segments of the 

 body and feet are similar or uniform in structure, and 

 not alternately furnished or destitute of cirrhi and scales, 

 as in these latter. The branchiae are well developed, 

 and assume the form of arbuscles, tufts, or crests, which 

 are attached in an uninterrupted series to the back, or 

 to the base of the feet. The head is distinct, the pro- 

 boscis is not furnished with jaws, and the feet are armed 

 with only a single bundle of simple bristles oil each 

 branch, and are destitute of spines. 



Family III.— EUNICIDiE. 



The EnnicidcB, agreeing with the Amphinomidm in 

 wanting elytra, and in having the segments of the 



body uniform in structure, nevertheless differ from 

 them in several important characters. The organs 

 of mastication, for instance, attain in these ani- 

 mals the highest degree of development. The 

 proboscis, instead of being, as 

 in the Amphinomes, jawless, is 

 armed with several pairs of horny 

 jaws, articulated with each other, 

 ",'/,, and approximated beneath so as 



' ■ ■ to rest on a sort of under lip of 



a similar horny texture. The 

 body is vermiform, and the seg- 

 ments are numerous and narrow, 

 but the first and second are with- 

 out feet. The others have feet 

 composed of only one branch, 

 and furnished with two cirrhi, 

 and with spines as well as 

 bristles. These latter are both 

 simple and compound. The 

 branchice in some of the species 

 are wanting, whilst in others they 

 are well developed and in the 

 torra of pectinated filaments, either straight or spiral, 

 and inserted above the dorsal cirrhus along a more 

 or less extensive portion of the body. The linear- 

 elongated general form of the body, which indeed 

 is almost cylindrical, but tapered posteriorly, render 

 the Eunices a connecting link between the Amphi- 

 nomes already described and the succeeding family of 

 Nereides. The eyes are sometimes very distinct and 

 two in number ; at others they are scarcely dis- 

 cernible. The antennae vary in number and size, in 

 some species being long, and five, seven, or even nine 

 in number; whilst in others they are short, and only 

 two or three. Other species again have none at all. 



Family IV.— NEREIDIDjE {The Nereides or Sea 

 Centipedes). 



The family of Nereides is a numerous one. The 

 body is always slender, linear, more or less cylindrical, 

 and divided ipto a very great number of segments, each 



Fig. 2Pa 



Nereis margaiita^'.^i*. 



side ; hence, from their general resemblance to these 

 animals, thej' are known by the name of Sea Cen- 

 tipedes. 



The head is distinct, but variable in form, and is 



furnished with generally well developed antennse, 



usually four in number ; and besides these in many 



species a certain number of tentacles, more or less well 



Vol. II. 



provided with a very oistinct projecting foot on each 

 developed, are to be seen on each side. The proboscis 

 is a powerful organ, always very thick and very long, 

 sometimes cylindrical in shape and sometimes club- 

 shaped. It is generally armed with two, or sometimes 

 four horny, scimitar-sliapcd, cutting jaws, denticulated 

 along the inner margin, though in a few species these 



2r 



