scope ot this work. Unfortunately, it is necessary to use 

 some of the mouthparts in the following key (e.g., see 

 couplets 6, 29, 31, and 47) and for the purposes of using 

 the key the following brief discussion should suffice. 

 First, the user of the key must make sure to observe the 

 proper mouthpart. Figure 7 illustrates their in situ loca- 

 tion on the ventral side of the cephalosome. In order from 

 anterior to posterior one encounters the mandibles (Mdl, 

 the maxillulae (Mxl), the maxillae (Mx), and the max- 

 illipeds (Mxp). The complete mandible consists of a 



praecoxa (with a toothed cutting edge), a coxa-basis, an 

 endopod, and an exopod (Fig. 7). The complete maxilla 

 consists of a syncoxa with endites, a basis, and an en- 

 dopod (Fig. 7), and the complete maxilliped consists of a 

 coxa, a basis, and an endopod (Fig. 7). Each mouthpart 

 theoretically consists of all the above listed parts (and 

 thus the word "complete" prefaces each description). 

 However, in any given species various parts may be 

 reduced or absent, e.g., couplet 29 of the key (Fig. 46) 

 refers to a maxilliped without a coxa and without an en- 



COXA 



PRECOXA 



COXA BASIS 



PRECOXA 



Figure 7. — Upper portion illustrating ventral view of cephaloBome with positioning of the appendages, i.e., ros- 

 trum (R), antennule (A ), antennae (A ), mandible (Md). maxillula (Mxl), maxilla (.Mx), and maxilliped (Mxp). 

 Lower portion showing enlargement of the various mouthparts, illustrating details. 



