GENERAL CHARACTERS. 



TABLE of the External Organs of the Amphipoda, with the Letters respec- 

 tively attached to each, as employed throughout the engravings in this work. 



C Cephalon .... 



H to Pereion 



P to Z Pleon 



(C) a Eyes 



b Superior antenna : 1, first; 2, 

 second; 3, third joint of pe- 

 duncle; 3", secondary ap- 

 pendage; 4, flagellum. 

 c Inferior antennae : 1, first; 2, 

 second ; 3, third ; 4, fourth ; 



5, fifth joint of peduncle ; 



6, flagellum. 



d Mandible; d" mandibular ap- 

 pendage. 



e First maxilla, or first siago- 1 

 nopodos* j 



/ Second maxilla, or second \ 

 siagonopodos . . J 

 g Maxillipede, or third siago- > 

 nopodos f 



(H to 0) h 1st Gnathopodos, represent- "i 

 ing the 2nd maxillipede, > 

 or fourth siagonopodos. J 

 i 2nd Gnathopodos, represent- ~) 

 ing the 3rd maxillipede, > 

 or fifth siagonopodos . J 

 1st Pereiopodos 

 2nd do. ... 



3rd do. ... 



4th do. ... 



oth do. ... 



1st Pleopodos. 

 2nd do. 



Head. 



Body. 



Tail. 



Eye. 



Superior antennas : 1, first; 2, 

 second; 3, third joint of pe- 

 duncle ; 3", secondary appen- 

 dage ; 4, flagellum. 



Inferior antennae : 1, first; 2, 

 second; 3, third; 4, fourth; 



5, fifth joint of peduncle; 



6, flagellum. 



d Mandible or jaw; d" man- 

 dibular appendage or 

 palpus. 



e First maxilla. 



/ Second maxilla. 



g Foot-jaw or peclipalp. 



h 1st 



2nd 



k 

 I 



m 

 n 

 o 

 (P to Z) p 



tl 

 r 

 s 

 t 



V 

 Z 



I- legs. 

 k 3rd 

 I 4th 

 m 5th 

 n 6th 

 o 7th 

 p 1st ) 



q 2nd [natatory legs. 

 r 3rd ) 

 * 1st ) 



t 2nd [ caudal appendages. 

 v 3rd J 



z Terminal joint or middle 

 tail-piece. 



The corresponding joints of all the limbs are marked with the same number, 

 and bear the same names throughout. We take one of the Gnathopoda as 

 the type. 



3rd 

 4th 

 5th 

 6th 

 Telson 



do. 

 do. 

 do. 

 do. 



or 1st LTOpodos 

 2nd do. 

 3rd do. 



1 Coxa 



1" Branchia 



1"' Plate of incubatory pouch 



2 Basos 



3 Ischium 



4 Meros; 4", inferior angle . 



5 Carpus; 5", inferior angle . . 



6 Propodos ; 6',palma ; 6", inferior angle ; 



6'", inferior margin; 6"", superior 



Coxa. 



Thigh. 

 Knee. 



Metacarpus ; 4", inferior angle. 

 Wrist ; 5", inferior angle. 

 Hand; 6', palm ; 6", inferior angle ; 

 6"', inferior margin ; G"", supe- 



margin. 



Dactylos;7", Unguis 



nor margin. 



Finger ; 



* This name is here suggested as the Greek equivalent for the Latin name of the five pairs 

 of appendages succeeding "the mandibles, which were collectively termed pates-mdchoires by 

 Cuvier, Savigny, &c. The levres superieure and iuferieure of these authors are omitted for 

 the reasons assigned in the following page. (T. 0. AY.) 



B 2 



