I40 INVERTEBRATE ANIMALS. 
which is placed on the under surface of the head, and is pro- 
vided with a complicated series of masticatory organs. It is 
Fig. 63.—Morphology of the Lobster. 1. Lobster with all the appendages re- 
moved except the last pair of the abdomen, and with the abdominal segments 
separated from one another: ca Carapace; ¢Telson. 2. The third abdominal 
segment, showing swimmerets. 3. One of the last pair of foot-jaws, carrying 
a gill (g). 
unnecessary to describe these minutely, but it should be noticed 
that they are all modified limbs, and therefore differ altogether 
from the jaws of the Vertebrate animals. That this is their real 
