10 G. 0. Sais. 



of simple cylindrical form. The last joint is constricted at 

 the base, and gradually widens distally, terminating in 2 

 unequal lobes, the anterior short and broad, the posterior 

 rather prominent, and at first sight looking like a distinct 

 terminal joint. Both these lobes are edged with numerous 

 slender ciliated setæ forming tog-ether a dense apical fascicle, 

 which may be spread out in a fan-like manner. The number 

 of the setæ is about 16 in all, 10 of them issuing from the 

 anterior lobe, and gradually diminishing in size outwards. 

 The outer ramus, which is very movably articulated to the 

 basal part, is comparatively poorly developed. Whereas in 

 other Diaptomidæ this ramus, as a rule, considerably exceeds 

 the inner one in length, in the present form it is scarcely as 

 long, and very much narrower. It is composed of 7 joints, 

 the 1st of which is rather short, cup-shaped, and naked, 

 whereas all the other joints are setiferous. The 2nd joint 

 is considerably longer than the next succeeding ones, the 

 4th, 5th and 6th being particularly small. All these joints 

 carry at the end a single ciliated seta. The last joint is 

 much longer than any of the others, fully half as long as 

 the remaining part of the ramus, but is very narrow. It 

 carries, at about the middle, a comparatively short seta, 

 whereas from the tip 3 very long setae originate. 



The anterior lip (see fig. 6) has the form of a rather large 

 flap-shaped prominence arching over the oral orifice, and slightly 

 trilobate at the tip, which is clothed with delicate hairs. 



The posterior lip (ibid.) exhibits 2 diverging lappets, 

 the somewhat incurved tips of which are densely ciliated. 

 Between the two lips the masticatory parts of the mandibles 

 are squeezed in. 



The mandibles (fig. 7) have the body rather strong and 

 highly chitinized, with the masticatory part well defined by 



