32 COMPARATIVE ANATOMY. 



XIII th , XII th , XI th , X th pairs, (ambulatory legs,) 



are similar to the fourteenth pair, but each possesses a 

 long curved membranous appendage, which ascends from the 

 ' coxopodite,' and in the natural condition penetrated into the 

 branchial chamber. This is the ' epipodite.' Attached to each 

 ' coxopodite ' may also be seen a lamellar gill. 



In the twelfth, eleventh, and tenth segments the 'propodite' 

 is prolonged outwards into a process which bites against the 

 ' dactylopodites,' and so forms the chelaB, which in the tenth 

 pair are of great size, 



IX*, VIII th , VII th pairs. (Maxillipeds) 



Each maxilliped is composed of three divisions, articulated 

 to a ' coxopodite/ In the first maxilliped [No. ix.], the outer- 

 most of these three divisions, the ' epipodite ' is a curved lanceo- 

 late lamina. A little in front of it is a gill, likewise attached to 

 the ' coxopodite.' The middle division is a many-jointed palpi- 

 form filament, which corresponds to the ' exopodite.' The 

 innermost element is the seven-jointed ' endopodite.' The 

 second pair of maxillipeds [No. vill.] much resembles the first, 

 but the ' endopodite ' is smaller and somewhat flattened, re- 

 sembling the foliaceous ' endopodite ' of the first pair. In the 

 third pair [No. vn.] the ' endopodite ' has been split into an 

 inner flattened plate-like lamella and an outer flattened fila- 

 ment. The ' exopodite ' is small, but the ' epipodite ' is large, and 

 in the specimen directed backwards. 



VI th , V th pairs. (Maxillce) 



In the first pair [No. VI.] the ' endopodite ' has been split into 

 five divisions, and is in consequence somewhat foliaceous. The 

 ' exopodite ' is a flattened filament. The ' epipodite ' is curved in- 

 wards. The ' endopodite' of the second pair [No. v.] differs 

 from that of the first in having only three divisions. The ' exo- 

 podite ' and ' epipodite ' are absent. 



