462 



CRUSTACEA. 



different form and adaptation in the various groups. As a rule, the 

 anterior pairs are modified to assist in taking up food and are moved 

 nearer the mouth ; these are the maxillipeds, which, with regard to 

 their structure, hold an intermediate position between jaws and feet. 

 In the Decapoda (fig. 362) three pairs of appendages have the form 



IML. 362. Male and female of Aafaeiix .fluviat'ilh seen from the ventral side. In the male the 

 ambulatory and abdominal feet of the left side have been removed ; in the female the am- 

 bulatory feet of the right side and the maxillipeds of both sides. A' antennules; A", 

 nntenna? ; PI, scale of antenna ; Md, mandible vs ith palp ; MX', Jl/j", first and second maxillre 

 Mxf to -l/j/ : , the three pairs of maxillipeds ; Goe, genital opening ; Doe, opening of the 

 green gland ; I", 1"" , first and second abdominal foot ; Or, eggs ; A, anus. 



of maxillipeds, so that there are only five pairs of legs left on the 

 thorax. In the Stomatopoda the first five pairs of thoracic append- 

 ages are modified to form maxillipeds and there are only three pairs 



