110 G. 0. SARS. CRUSTACEA. [norw. pol. exp. 



anteriorly-curving setae, 6 of which issue close together from the tip, the other 

 4 from a slight protuberance of the anterior edge near the base. These 2 

 groups of setae are only separated by a very short interspace. 



The oral orifice occurs, at rather a long distance from the antennae, at 

 the tip of an obtuse protuberance projecting from about the middle of the 

 ventral face of the cephalic segment (see fig. 2). It is bounded in front by 

 a sfight chitinous lamella, representing the anterior lip; and on each side of 

 it the extremely small mandibles and maxillae have their place. 



The mandibles (fig. 5) each form a very small, but highly chitinized 

 piece, the extremity of which is abruptly incurved, and produced to 2 strong 

 cutting teeth, finely denticulated along one of their edges, and each accom- 

 panied by a slender bristle. The palp is wholly absent. 



The maxillae (fig. 6) are still smaller than the mandibles, and more 

 membranous in structure, each carrying a single ciliated bristle inside, 

 and 4 such bristles outside, attached to a slight lamellar expansion, the tip 

 itself being conically produced and incurved, with 2 small apical spines. 



The anterior maxillipeds (fig. 7) originate just behind the buccal protuber- 

 ance, and extend obhquely in front, so that their extremities project at the 

 sides of the oral orifice. They each consist of a thick, muscular basal part, 

 to the end of which a more highly chitinized and incurved piece is movably 

 articulated. This piece, which is of no considerable size, projects at the end 

 in 2 claw-like teeth, fringed along one edge with closely-set denticles in a 

 comb-fike manner. The teeth are somewhat unequal in size, the outer one 

 being the larger; and, as in the mandibles, they are both accompanied by 

 a slender bristle. 



The posterior maxillipeds (fig. 8), which originate immediately behind the 

 anterior, are rather powerful, and pronouncedly prehensile, exhibiting besides 

 the basal part, a dilated hand, upon which a strong, claw-like dactylus admits 

 of being impinged. The basal part is quite simple, without any armature. 

 The hand is twice as long as the basal part, and oval in form, with 2 strong, 

 denticulated spines inside. The dactylus is very strong, somewhat shorter 

 than the palm, and coarsely denticulated along the inner edge. 



Of legs, 5 pairs are present, the 4 anterior ones being natatory, whereas 

 the last pail' are simple. 



