Euphausiidæ. 33 



as a rule, extended laterally. The scape is divided into 2 

 sharply defined segments, the outer of which is the shorter, 

 and slightly widens distally. The rami are equal in length, 

 the inner oue being uniarticulate and provided with 5 nata- 

 tory setæ, 4 of which issue from the tip, the 5th from a 

 separate ledge of the inner edge. The outer ramus has 

 a rather flexible outermost part, which is divided into several 

 short articulations, each carrying a natatory seta. The number 

 of these setæ is 7 in all, 2 or 3 of which issue from the last 

 articulation. They successively diminish in length distally 

 and, like those originating from the inner ramus, are very 

 finely plumous. 



The anterior lip (see fig. 4) is well defined, forming a 

 rounded lobe, which in a lateral view of the animal, pro- 

 jects beyond the edges of the carapace. Immediately in 

 front of it, the small prominence containing the ocellus is 

 observed lying between the insertions of the antennulæ. 



The posterior lip (fig. 8) is partly concealed by the 

 maxillse, so that it can only be distinctly seen by dissection. 

 It consists of 2 juxtaposed lobes obtusely truncated at the 

 tip, and still without any marginal cilia. 



The mandibles (fig. 7) are still without palps, the place 

 of the latter being occupied by a short conical projection 

 not defined from the body of the mandible. The masticatory 

 part is securiform, with the anterior corner (the cutting 

 part) divided into several strong teeth, the posterior (molar 

 expansion) obliquely truncated, and exhibiting a finely fluted, 

 triturating surface. Between the two parts a narrow, movable 

 plate is seen, tipped with a number of fine spinules. 



The anterior maxillæ (fig. 9) consist each of 3 principal 

 parts, viz., the basal part, the palp, and the exognath. The 

 basal part is apparently composed of 2 imperfectly defined 



