NO. lO 



IKhJJlN'G 0I<(;AN.S ok AUAc IINIDA - SN()IK;RASS 



which usually arc closely associated with the mouth. 'I'hcjugh Hansen 

 and Sorensen (1904), therefore, are morphologically correct in des- 

 ignating the pedipalp coxae "mandibles," the term is not appropriate 

 in a functional sense, inasmuch as the pedipalp coxae do not form 

 true jaws in any arachnid. Arachnology has the term pedipalp for 

 the second pair of segmental appendages, and, though the latter arc 



Fig. 3. — Structure and niubculature of the chcliccrac. 



A, Litnutus polyphemiis L., Xiphosurida. left chcliccra of a younj? specimen, 

 lateral. B, Patiditius sp., Scorpionida, chcliccra. C, Lciobimum sp., Phalangida, 

 left chclicera and muscles, lateral. D, same, distal segments of chcliccra. showing 

 both muscles of movable finger. E, Centruroidcs sp., Scorpionida, movable 

 finger of chcliccra and its muscles. F, two-scumcntcd chcliccra of a solpugid. 

 G, two-scpmcntcd chclicera of a spider, Eurypclma lu-rt:i Giamh.. lacking a 

 fixed finger. 



not always palpi form, liiere would sccin to be no good reason for 

 calling them either maxillae or mandibles. 



The coxae of the pedipalps in most of the arachnids are directed 

 horizontally forward at the .sides of the mouth (fig. 2 .\. fICx), 

 and, as already noted, their dorsal surfaces are usually united with 

 the cpistome (Epst), which thus forms an interco.xal bridge. The 

 lines of union are generally distinct grooves ( B. crs), which are 



