THE B0R8E8H0E CRAB. 
95 
Class II. — Podostomata {King-crab, Eurypterus, and 
Trilobites). 
Order 1. Merostomata. — The only living representative 
of this ord^r is the horseshoe or king-crab {Limnlus Poly- 
phemus, Fig. 122), which ranges from Casco Bay, Maine, 
to Florida and the West Indies. 
The body of the king-crab is very large, sometimes nearly two 
Fig. 119.— Common Shore-crab (Cancer trromfits). Natural size. FromEmertr^ 
feet in length ; it consists of a head composed of six segments and 
an abdomen with nine segments, the ninth (telson) forming a long 
spine. The head is broader than long, in shape somewhat like that 
of Apiis, with a broad flat triangular fold on the under side. Above 
are two large lunate compound eyes, near the middle of the head, 
but quite remote from each other, and two small compound eyes sit- 
uated close together near the front edge of the head. There are no 
antennae, and the six pairs of appendages are of uniform shape like 
legs, not like mandibles or maxillae, and are adapted for walking; 
the feet are provided with sharp teeth on the basal joint for retain- 
