HORSESHOE-CRAB 295 
It lives on sandy and muddy shores below low-water mark, where it bur- 
rows beneath the surface. At the breeding season— May, June, and 
July — it comes ashore to deposit its eggs near high-water mark. The 
crabs come up the beach in pairs, the male being the smaller and riding 
on the back of the female, holding on by short feet provided with nip- 
pers, which are peculiar to the males. Sometimes the female is ac- 
companied by several males, each one holding on to the tail of another 
and forming a string of animals. After the female has deposited her 
eggs in a hole excavated by her for the purpose, the male covers them 
with milt, and they then return to the water, leaving the eggs to, be buried 
in the sand by the action of the waves. The eggs hatch in July and 
August, and sometimes the beach is literally alive with the young crabs, 
which, however, soon disappear, : 
and are not seen again until they 
are well grown. After the 
spawning season the adults are 
not very often seen, but usually 
their empty shells, abandoned 
in moulting, may be found on 
the shore. The horseshoe-crab, 
also called king-crab, is espe- 
cially interesting from the fact 
that it is the last survivor of 
an otherwise extinct group of 
animals. Its relationships with 
classes which have become ex- 
tinct, its nearest relatives being 
fossils, make it difficult to class- 
ify definitely with existing forms. 
Formerly it was regarded as a 
crustacean ; now it is classed by 
some authors with the Arachnida, 
along with scorpions and spi- 
ders. It has the characteristics 
of both groups. There are only 
two known species of Limulus 
in the world; the other, Limu- 
tus moluccanus, lives on the 
eastern coast of Asia. L. poly- 
phemus often measures a foot in 
diameter. The body is com- 
posed of three parts. The front 
portion, or cephalothorax, is 
broad and semicircular, with Under sae of ua aura ae poly. 
pusterior angles ending In’ Ziheaing abdominal sppendage; m, month; 0 
points. Near each side of its ener p, telson; tigen Ee eephalo- 
dorsal surface is a pair of large thoracic limbs. 
compound eyes covered with ; 
thickened cuticle, and near the center line of the shell, at the base of the 
first spine, a pair of small, simple eyes. The second portion is the ab- 
domen, and the third a long, movable spine attached to the last segment 
of the abdomen and between two terminal points of the horn-like covering. 
