REPORT ON THE SCHIZOPODA. 153 



These bodies represent the first indication of the compound eyes ; Init neither pigment 

 nor any trace of visual elements have appeared. All that can now be seen within these 

 corpuscles consists of a bunch of densely crowded, glistening posteriorly diverging fibres, 

 easily recognised as representing the peculiar luminous organ that occurs in the pedicles 

 of the eyes of the adult animal. 



The anteunulse (fig. 8) still constitute simple, somewhat curved stems, tapering 

 toward the apex, but differ from those in the preceding stage in the apical part being 

 marked off from the remainder as a distinct terminal joint, rei)resenting the outer 

 flagellum. This joint juts out interiorly as a small denticle, bearing, moreover, at the tij), 

 three slender bristles, and two translucent sensory appendages of unequal length. Of the 

 inner flagellum, no trace has yet appeared, its place Ijeing occupied merely by two 

 bristles springing from the end of the basal section or peduncle. 



The antennae (fig. 9) have the two segments of the basal part more distinctly defined, 

 the distal segment being somewhat shorter than the proximal, and slightly dilated toward 

 the end. The terminal branches, too, appear more fully developed and nearly as long a.s 

 the basal part. The inner liranch is simple cylindrical and iiDU-artieulate, bearing at the end 

 four very long ciliated setre and at the inner edge two smaller ones, the proximal setae, 

 very short and sj^iniform. The outer Ijranch, on the other hand, has the apical part, 

 rapidly tapering, and di\dded into several (about five) ver}' short articulations, provided 

 at the inner edge with slender natatory setae, successively diminishing in length toward 

 the apex. 



The anterior lip (see figs. G and 10) has become more distinctly marked ofi" from the 

 body-wall, forming a rather large oboval prominence, the posterior edge of which covers 

 over the inner ^Jart of the mandibles. 



The posterior lip (fig. 11) exhibits quite a normal aspect, its lobes being irregularly 

 rounded and delicately ciliate along the inner edge. 



All the three ventral limbs — in the preceding stage but faintly indicated — have now 

 become active organs for conveying food to the mouth ; hence they are mobile and armed 

 with bristles and spines (see fig. 6). 



The mandibles (see figs. 10, 12) have the inner (masticatory) part expanded in the 

 usual manner, and exhibit, moreover, anteriorly an acute projection arising, it would seem, 

 from the point where, in the Naujilius stage, the mandibular leg originates. Of a palp, 

 on the other hand, no trace whatever can be found. The armature of the cutting edges 

 (see figs. 13, 14) is well developed, though somewhat dissimilar to that in the adult 

 animal, resembling rather the armature found in some Mysidae. As occurs in the latter, 

 the anterior part is divided into several strong and very closely arranged teeth, forming 

 together two partly superposed portions, which in the two mandil)les exhil)it a somewhat 

 different shape. Between this dentate part and the molar jirotuberance occurs a short 

 dentiform projection, and at the base of the latter is affixed on both mandibles a very 



(ZOOL. CHALL. EXP. PART XXXVII. 188?.) Oo 20 



