CYCLOPOIDEA. 



1035 



47, 48 (inverting the latter), evident relations to the forms among the 

 second antenna will be observed. The joints are numbered so as to 

 exhibit their normal relations. 



Anterior pair of legs.— This pair is one of the most various in form, 

 in the Cyclopoidea. In some species it is rudimentary, the preceding 

 being in this case unusually enlarged. In others it is long and 

 seven- or eight-jointed, with slender setae to the joints (fig. 82). Still 

 others, in which there are as many joints as in the last, have the 

 last five short, so that the setae form together a long thick pencil 

 (f. 83.) In others, again, the organ is subcheliform (figures 84, 85, 86, 

 Plate 71), or it terminates in a claw (figure 87), or in a few short 

 setae (figures 88, 89), or in one or two oval plates. The relations of 

 figures 82 and 83 are obvious from the figures ; and the passage into 

 the cheliform variety takes place, in the same manner as in the poste- 

 rior antennae. In figures 84 and 85 there is a setose prominence on 

 the large joint corresponding to the hand, to which the claw is opposed 

 in grasping. 



In figure 89, there is the same general structure ; and if the last 

 joint and the prolonged apex of the penult joint were both lamellar, 

 the organ has a bilamellar termination, as above alluded to. 



In figure 90, the organ is nearly rudimentary. Moreover, it is 

 two-branched. And if we compare it with figure 77 or 78, which 

 represents a maxilliped, we may infer that the maxilliped corresponds 

 to one branch (3' 4'), and these feet we are describing, to the other 

 branch. This appears from the setulose setae of the branch, 3' 4', 

 which are identical with those of the maxilliped referred to. Figure 

 91, is another rudimentary form (three or four times more magnified 

 than figure 90), and the whole probably corresponds to the shorter 

 branch of figure 90. Figure 92 is another example of the same. It 

 is closely related to figure 79, and is actually from the same species ; 

 the organ is quite small, while the maxilliped, as is seen in figure 79, 

 is comparatively large. 



These organs sometimes differ in the sexes. Figures 84 and 85 

 are male forms, and figure 87 a female form of this organ, in one of 

 the genera. The enlargement in the male takes place to enable it to 

 use them for grasping in coition. 



This pair of legs is often called a pair of maxilla-feet, jaw-feet, or 

 masticatory feet. It is more correct and better sustained by analogies 



