CRUSTACEA — WIIITELBGGE, 



•251 



Body viewed from above. 

 Fig. 24a. 



length to the first sci^inent of the peraeon. Frontal margin 

 with an indistinct median process, 

 lateral margins somewliat thick- 

 ened and bidentate. The basal 

 joints of the antennie are visible 

 from above, their inner bases are 

 separated by the inferior and 

 superior frontal processes. First 

 peraeon segment longer than 

 either of the three subequal seg- 

 ments following, seventh segment 

 much the shortest. Pleon equal 

 in length to the six preceding- 

 segments ; the penultimate seg- 

 ment is short, and the lines 

 indicating coalescence are faintly 

 marked. Ultimate segment 

 strongly convex, the sides are con- 

 verging, the extremity is broadly 

 rounded and entire. The first 

 epimeral process has the anterior 

 border oblique and produced in 

 front beyond the eye, the posterior 

 border is transverse, and the 

 extremity acute ; the second and third are broadly i'ounded> 

 the fourth is acute, the fifth is broad and obtusely rounded, the 

 sixth is subacute, and the seventh obliquely truncated. Side 

 plates of the pleon rather long, with the anterior margin rounded, 

 and the posterior extremity acute. Eyes lateral, prominent, 

 posteriorly deeply imbedded in the first peraeon segment. First 

 joint of the anterior antenna? one-third longer than broad ; the 

 second is not so long as the width of the first ; third joint slender, 

 nearly as long as the first. Flagellum longer than the peduncle, 

 consisting of ten joints, the second being the shortest. Peduncle 

 of second antennae shorter than the flagellum : the first two 

 joints of the former are equal ; the fourth is equal to the second 

 and third combined. The flagellum has thirteen joints, the 

 third of which, is much the longest. Mandibles slender, the 

 apical half narrow and suberect, cutting edge with four denticles; 

 there is a large tridentate process below and a bunch of denticu- 

 lated spines. Molar tubercle small, distinct, and situated close 

 to the masticatory lobe. Lobes of the first maxillae rather 

 widely separated, the inner narrow and tipped with four 

 pectinated sette, the outer lobe is curved and diminishes in 

 width towards the apex ; the latter bears eight or nine strongly 

 denticulated spines. The lobes of the second maxillte ai^e rather 

 unequal in length and breadth. Palp of maxillipedes short and 

 comparatively broad, with the setiferous lobes well developed ; 



