B. IT.] THE HISTORY OF ANIMALS. 81 



legs and feet, and how many they have, and in what direc- 

 tion, and that, for the most part, they have the right claw 

 larger and stronger than the left; I have also mentioned 

 their eyes, and that most of them are able to see sideways. 

 The mass of their body is undivided, and so is their head, 

 and any other part. 



2. In some the eyes are placed immediately below the 

 upper part, and generally far apart ; in some they are placed 

 in the middle, and near together, as in the Heracleot carcini 

 and the maia. The mouth is placed below the eyes, and 

 contains two teeth, as in the carabus, but they are long 

 and not round, and over these there are two coverings, 

 between which are the appendages, which the carabus 

 also possesses. 



3. They receive water through their mouth, opening the 

 opercula, and emit it again by the upper passage of the mouth, 

 closing the opercula by which it entered; these are im- 

 mediately beneath the eyes, and when they take in water 

 they close the mouth with both opercula, and thus eject 

 again the sea-water. Next to the teeth is a very short 

 oesophagus, so that the mouth appears joined to the sto- 

 mach, and from this proceeds a divided stomach, from the 

 middle of which is a single thin intestine ; this intestine 

 ends externally beneath the folding of the extremity, as I said 

 before. Between the opercula there is something resembling 

 the appendages to the teeth of the carabi ; within the abdo- 

 men is an ochreous chyme, and some small elongated white 

 bodies, and other red ones scattered through it. The male 

 differs from the female in length and width, and in the abdo- 

 minal covering, for this is longer in the female, farther from 

 the body, and more thick-set with appendages, as in the female 

 carabi. The parts of the malacostraca are of this nature. 



CHAPTER IV. 



1. THE testacea, as cochlea?, 1 and cochli, 2 and all that are 

 called ostrea, 3 and the family of echini, are composed of 

 flesh, and this flesh is like that of the malacostraci, for it is 

 internal; but the shell is external, and they have no hard 

 internal part. But they have many differences amongst 

 themselves, both in regard to their external shells and their 

 1 Land snails. ? Marine. 3 Bivalves. 



