On Steno cyp ris Chevreuxi. 1 3 



close together, curving downwards in front of the outer 

 joints, and extending as far as the tips of the terminal 

 claws. These setæ are finely ciliated, and during the 

 swimming motions of the animal, are spread in a fan-like 

 manner, to counterbalance the effect of those issuing from 

 the superior antennæ. The 2nd joint of the terminal part 

 is but little more than half as long as the 1st, and also 

 considerably narrower, forming with the same a more or less 

 pronounced geniculate bend. It is provided on each side, 

 about in the middle, with a fascicle of slender bristles, and 

 is produced at the end anteriorly to a knob-like projection 

 carrying 3 very strong claws of somewhat unequal length. 

 The last joint is very small, and apparently firmly connected 

 with the 2nd. It is (see fig. 2, a) of simple cylindric form, 

 and carries on the tip 2 unequal claws, and 3 small, hair- 

 like bristles. The claws are much smaller than those 

 issuing from the preceding joint, which in fact extend some- 

 what beyond them. 



The anterior lip (figs. 3, 4) is rather voluminous and 

 produced in front in a hood-like manner. It terminates 

 posteriorly with a sharpened edge limiting the oral aperture 

 in front. Within it, several muscles are seen to spread, 

 which may serve for lifting it to a certain extent; and 

 a rather complicated system of chitinous stripes anastomosing 

 with each other, and partly continued around the oral 

 aperture, may also be distinctly traced. 



The posterior lip (ibid, and fig. 5) is in the form of a 

 thin plate bounding the oral aperture behind, and placed 

 almost vertically. It is strengthened on each side by a very 

 strong chitinous rod, which expands at the end to a dark 

 horn-coloured lamella, divided into 7 or 8 coarse denticles. 

 This lamella is placed transversally, and is somewhat incurved, 



