434 PROF. G. O. SARS ON 



straight forwards. Both flagella are distinctly defined and of 

 about equal size. They are, however, still rather short, scarcely 

 exceeding half the length of the peduncle, and do not exhibit any 

 trace of subdivision. At the tip each flagellura carries a bundle 

 of small bristles, and on the outer flagellum, moreover, two bundles 

 of delicate sensory filaments have developed, attached to well- 

 marked ledges of the anterior margin. 



On the antennce (fig. 4) the scale is rather large and oblong- 

 oval in form, with the outer edge straight and perfectly smooth, 

 . terminating in an acute tooth-like projection. The distal part 

 of the scale is obliquely truncated and projects somewhat beyond 

 the tooth of the outer edge. It is, like the inner slightly convex 

 edge, fringed with a regular row of slender ciliated setse, about 

 sixteen in number. The flagellum considerably projects beyond 

 the scale and points straight forwards. At its base a short joint 

 has been cut off representing the peduncular part. The terminal 

 part of the flagellum is still qviite simple, cylindric, and without 

 any trace of subdivision. 



The mandibles (fig. 6) have the cutting-edge divided into a 

 number of small denticles, behind which some minute bristles are 

 attached. The molar tubercle may also be distinctly traced. 



The anterior maxillce (fig. 7) exhibit a structure nearly agreeing 

 with that found in the adult animal, the middle, or masticatory 

 lobe being rather sti-ong and securiform in shape, with a row of 

 well-developed denticles along the straight inner edge. The very 

 small terminal lobe, representing the palp, is attached outside 

 the masticatory lobe to a well-marked ledge, and carries on the 

 tip three i-ather slender bristles. The basal lobe is cordiform and 

 fringed with ciliated setiB. 



On the posterior maxillce (fig. 8) the exopodal plate is now well 

 defined and mobile, its anterior part being edged with slender 

 finely ciliated setse, and the posterior part exserted to a narrow 

 lappet carrying on the tip a few setee. Of the lobes belonging to 

 the endopodal part the outermost one is cut off as a distinct 

 joint, representing the rudimentary palp or endopodite proper ; 

 the remaining three lobes are edged with well-developed spines 

 and seta3, and constitute the masticatory part of the maxilla. 



The three pairs of maxillipeds (figs. 9-11) are less conspicuously 

 transformed, though the 1st pair (fig. 9) by the greater size of 

 the basal part and the considerable reduction of the endopodite 

 somewhat approach the structure of these appendages in the 

 adult animal. The charactei"istic difl[erence between the tAvo 

 posterior pairs observed in the adult animal is, however, not 

 yet apparent, the endopodite being in both (figs. lO&ll) of a 

 very similar appearance and agreeing with that found in earlier 

 larval stages, with the only exception that the setae clothing the 

 joints are more fully developed. The exopodites in all three 

 pairs a,re unchanged, acting still as natatory organs. 



The two anterior pairs of legs, or the cheli]jeds (fig. 12), are of 

 exactlv the same structure, the endopodite of both terminating in 



