278 
CRUSTACEANS. 
gigantic andania, Andania gigantea (nat. size). 
principal segments bearing three large and pointed spines, which have their edges 
armed like the blades of a saw. Very different is Andania, which is one of the 
largest of amphipods, reaching a length of 2 inches. Many members of the group 
construct tubular dwelling-places, in 
which they take shelter, and lay their 
eggs. For instance, the British Am- 
phitha rubricata, which is a brilliant 
crimson colour, builds a nest of particles 
of seaweed cemented together with 
threads; while another species of the 
same genus {A. littorina ) makes a tube 
by cementing together the edges of a 
leaf of growing weed, so as to make 
a tube open at both ends. Again, 
according to Bates, Podoacerus capil- 
latus “ builds its nest in a very bird¬ 
like manner in submarine forests; the 
nests consist chiefly of fine thread-like 
material, woven and interlaced, being 
established firmly in the branches of 
zoophytes ; some small extraneous frag¬ 
ments are often bound with it, but these 
appear more the result of accident than intention. The form of the nest is 
somewhat oval, the entrance being invariably at the top. These nests are evidently 
used as places of refuge.” 
In the tribe Caprellina the head has coalesced with the first segment of the 
thorax, and the abdomen is reduced in size, with most 
of its appendages wanting. The two principal families 
are the Caprellidoi, or skeleton-shrimps, and the 
Cyamidce, or whale-lice. In the former the thorax is 
cylindrical, and the abdomen, with its limbs, rud¬ 
imentary. I11 the typical Caprella the third and 
fourth thoracic segments are without legs, but bear a 
pair of branchial vesicles; the appendages of the 
second pair are developed into claspers, and those of 
the three last pairs are of the ambulatory type. 
These shrimps seldom swim, but climb amongst the 
branches of seaweeds and zoophytes. When at rest, 
they grasp the stems of the weeds with their hind- 
limbs, and, holding the body in an erect position, wave 
their long antennae in search of prey. In the whale- 
lice, which live parasitically upon cetaceans, the short 
and conical head is united to the first segment of the 
thorax, which consists of six free, flattened segments. 
As in Caprella, the third and fourth segments of the body bear no limbs, but are 
furnished with a pair of gills, usually turned over the animal’s back. In the 
skeleton-shrimp (somewhat 
enlarged). 
