42S PROF. G. O. SARS ON 



the animal from the ventral face (tig. 3). The two pairs of 

 antennae (a^ &, a") originate on eaeli side of a median slightly 

 convex area, the hypostome (H), the one pair, the antennnlfe («^), 

 occurring in front and inside the other pair, the antennpe {a ). 

 Fi'om the hind part of the hypostome the flap-shaped anteiior lip 

 (L) is seen to arise covering the inner parts of the mandibles. 

 The latter (M) are easily observed as two comparatively large, 

 transverse, bow-shaped eminences, and immediately behind them 

 in the middle the two rounded lobules of the posterior lip [1) are 

 clearly seen. Behind these parts the two pairs of maxillte have 

 their place, the 1st pair, or anterior maxillae (m^), lying inside and 

 slightly in front of the 2nd (vi^), which are extended obliquely 

 outwards. The maxillae are followed by three pairs of much larger 

 appendages (mp^-mp^) exhibiting a ver}^ similar appearance, each 

 consisting of a short basal part and two diverging unequal rami, the 

 inner one (endopodite) forming a short incurved stem, the outer 

 one (exopodite) a much larger, laterally extended natatory ramiis. 

 These three pairs of appendages, which are separated in the middle 

 by a somewhat irregular jiattened area (the sternal plastron), 

 represent the maxillipeds in the adult animal. Behind them not 

 even the slightest trace of any pedal buds is to be detected. 



The posterior division of the body, or metasome (figs. 1 & 2), 

 is rather slender, being a.bout twice as long as the anterior 

 division, and is composed of six well-defined segments, the last of 

 which is much the longest and very narrow. This segment passes 

 without any intervening suture into the caudal pla-te. The latter 

 is rather unlike that found in most other Caridean larvte and more 

 resembles in shape that part in the protozoea stage of Penceus. As 

 in that form, it is cleft by a deep median incision into two slightly 

 diverging lobes obtusely rounded at the end. Each lobe carries 

 six finely ciliated setae of rather iinequal length, the outermost 

 one and the innermost but one being considerably smaller than 

 the others. The 4th seta, counted from the outer side, is the 

 longest, equalling in length the last segment to the bottom of the 

 median incision. In some of the larvfe, which otherwise agreed 

 with that here figured, a A^ery small additional seta occurred 

 inside the others on each lobe (fig. 12). On the anterior caudal 

 segments slight traces of the epimeral plates could be detected, 

 those of the 4th and 5th segments terminating in an acute corner. 

 The ventral faces of the segments are somewhat convex ; but not 

 the slightest trace of pleopoda is as yet observable. 



Structure of the Appendages. 



The antennidce (fig. 4) are comparatively small, and each consists 

 of a simple biarticulate stem extended forwards. The proximal 

 joint is much the lai-ger and represents the peduncle. It is, 

 however, quite simple, without any trace of a subdivision and 

 exhibits no armature whatever. The distal joint is much 

 narrower than the proximal one, and also shorter, of oblong-oval 



