Amphinomid^. 
-ANNELIDA. - 
-Nekeidid^e. 
297 
most important characters. We give, as an illustration 
of this family, a figure of Aphrodita liystrix, the 
Porcupine Sea-rnouse, a native of our own shores. — 
See fig. 202, 
Fig. 202. 
Aphrodita hystrix. 
Family II. — AMPB[INOMID.i3<i (The AmpMnomes). 
The Amphiiiomes are distinguished from the Aphro- 
dilidce hy their generally elongated body 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 branchim 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 on each 
branch, and are destitute of spines. 
Family III.— EUNICID^. 
The Eanicidce, agreeing witli the Amplihiomidce 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 
branchiae in some of the species 
are wanting, whilst in others they 
are well developed and in the 
form 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 antennse vary in number and size, in 
some species being long, and five, seven, or even nine 
in number ; whilst iii others they are short, and onlj 
two or three. Other species again have none at all. 
Family IV. — NEREIDID.3!] (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 into a very great number of segments, each 
F!g. 203 
Nereis margaiitacea. 
side; hence, from their general resemblance to these 
animals, they 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 
Von. 11. 94 
provided with a very nistinct 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 horn}^ scimitar-shaped, cutting jaws, denticulated 
along the inner margin, though in a few species these 
