The 2nd pair of maxillipeds is much more slender than the 1st pair, 

 and also more simple in structure. At their base, 2 small rounded lamellae are 

 appended, which, in the ovigerous females, are fringed with long setae forming 

 together a broad fan, which projects within the incubatory cavity. It is some- 

 what doubtful whether these lamella? should be regarded as the epipodites or as 

 a pair of modified incubatory plates. 



The 3rd pair of maxillipeds are considerably larger than any of the 

 preceding pairs, and, as a rule, more or less completely cover all the other oral parts 

 below. The basal joint is very large ard curved, being sometimes produced at the end 

 outside to alinguiform setiferous lobe. In all the known forms, these limbs are pro- 

 vided at the base with well developed natatory exopodites; and this is also 

 the case with the next succeeding pair of limbs (the 1st pair of legs). In the 

 greater number of forms, also the 2nd pair of legs, sometimes, too, the 3rd pair, 

 carry similar appendages; and in the adult males the entire number of legs, with 

 exception of the last pair, are, as a rule, provided with well-developed natatory exopo- 

 dites, only the family Cumidce forming an exception in this respect. The presence of 

 these appendages is another character by which the Cumacea differ very materially 

 from the Edriophthalmia, and in which they evidently approach much nearer to 

 the lower Podophthalmia (Schizopoda). 



As regards structure, the legs (the number of which, accordingly, as in the 

 higher Crustacea, is only 5 pairs) are rather simple, none of them being cheliform or 

 even subcheliform. The 1st pair is generally the largest, and somewhat resem- 

 bles in structure the 3rd pair of maxillipeds ; but they are much more slender. They 

 extend forwards below the carapace, with their outer, doubly geniculated part 

 generally projecting far beyond its extremity. These legs seem to act chiefly as 

 a sort of imperfectly developed preying organs, and for conveying food to the mouth. 

 The 4 remaining pairs of legs are the true pereiopoda, or more properly, fossorial 

 legs. Of these the anterior pair differs slightly from the other 3, being some- 

 what intermediate in structure between them and the 1st pair. In all the legs, 

 as also in the maxillipeds, the normal number of 7 joints may generally be found. 

 Only in the 2nd pair does a fusion of 2 of the joints (the basal and ischial) 

 sometimes take place, whereby this pair, in such cases, appears to be only 6-ar- 

 ticulate. Of the joints, the coxal one is so firmly connected with the body, that, 

 on dissection, it is generally separated from its connection with the other part of the 

 leg. It is, however, always present, though often of very inconsiderable size. 

 The basal joint, on the other hand, is by far the largest of all the joints, and in 

 those legs which are provided with natatory exopodites, is considerably dilated 



