520 SUPPLEMENT 



largest, almost square, or triangular, occupying the place of 

 head or corslet, supporting two or four simple eyes, situated 

 laterally, the organs of mastication, two palpated feet, large, 

 in the talon form, terminated by a didactylous forceps, and 

 the first six feet; 2. of eleven other segments, but transverse, 

 annuliform, and on the first of which, the fourth, and last 

 pair of feet, appear to be inserted ; the subsequent rings com- 

 pose the abdomen. The mouth is formed, 1st. of two mandi- 

 bles, situated at the anterior and superior extremity of the 

 corslet, contiguous, advanced, and entirely uncovered in the 

 obisia, corneous, of a single piece in the form of a forceps, ovoid, 

 didactylous, and of which the external digit is mobile, denticu- 

 late, or ciliated ; 2. of two large palpated feet, or claws, ter- 

 minated also in a didactylous forceps, composed of six articu- 

 lations, the mobile digit included ; 3. of two jaws, formed by the 

 internal prolongation of the radical articulation of the claws, 

 valvular, a little gibbous, or convex in the middle, depressed, 

 and with reflected edges, near the interaal margins, joining along 

 these margins, thus closing the mouth inferiorly, and terminated 

 in a point ; 4. of a sternal tongue, situated in the interior of 

 the mouth, between the jaws and mandibles, cuspidated at its 

 superior extremity, and presenting, at each side of this point, 

 a small apj^endage, according to the observations of M. 

 Savigny. The younger Hermann had already observed this 

 piece ; he says that it is a conical papilla, embraced by two 

 sorts of valvules, (the jaws) and that it is doubtless the 

 proboscis of these animals. The feet are divided into five 

 {cJielifer, properly so called) or six articulations, (the ohisid) 

 according as the tarsus is composed of one or two pieces. 

 The extremity of the last articulation is always armed with 

 hooked, elongated, and approximated teeth, under which is a 

 small pellet. The articulation which corresponds to the 

 thigh is in general broader, and elongated. The length of the 



