112 stalk-i-:yki) Crustacea. 



gins i^pinulose ; the sixth are acute, and armed with a small spine at the 

 point, but otherwise unarmed. The telson, besides bearing the two sjiines 

 above-mentioned, is sparsely spinulose along its margin ; it bears two longi- 

 tudinal dorsal ridges, and its posterior end is subacute. 



The proximal segment of the first antenna) is short and broad, and is pro- 

 duced at the inner distal angle into a long, sharp, tooth-like process, which is 

 hairy along the basal part of the inner side, but not armed with spines ; the 

 outer side of the segment is swollen and furnished witli two small spines at 

 the distal end ; the second and third segments diminish successively in size; 

 the third segment bears two flagella, the upper and outer of which is only 

 one half as long as the lower and inner one ; the shorter one is composed of 

 about thirty segments, the lower one of about fifty. The basal segment of 

 the peduncle of the second antenna is short and broad, and carries a long, 

 slender, cylindrical process (phymacerite of Bate) on its inner side ; this pro- 

 cess is directed inward and forward, is nearly as long as the peduncle of the 

 antenna, obliquely truncate at the tip in the left one, while the one on the 

 right side is rounded at the tip ; the distal end of the phymacerite is free, 

 and does not slide upon the basal segment of the first antenna as it does in 

 Polychcles and Willcmoesia ; the second segment also is short and broad, and 

 bears an external foliaceous scale (scaphocerite) which is oval and hairy on 

 the margins, but destitute of spines ; its tip reaches to the end of the 

 peduncle; the third and fourth segments are longer, cylindrical, subequal; 

 the flagellum is about ecjual in length to the longer of the antennulary 

 flagella, and contains about fifty segments. 



The mouth is bounded in front by a large, protuberant labrum (Plate 

 XXX., Fig. 1, Q, and is Hanked by the broadly expanded mandibles (Plate 

 XXIX., Fig. 2). The latter are without molar areas; their crowns are ser- 

 rated on their cutting edges with fourteen triangular teeth, of which one at 

 the anterior angle, one in the middle, and two at the ])osterior angle are 

 larger than the others; the mandibular palpus is triarticulate, the terminal 

 segment setose. Directly below and hehind the base of the mandibles lie the 

 widely separated, palpiform lobes of tlie mctastoma (Plate XXX., Fig. 1, d^). 



The first maxilla (Plate XXIX., Fig. 2") is reduced to two slender, 

 strongly incurved, protognathal lobes, the anterior of which is the larger. 

 Both lobes are setiferous. There appears to be no trace of the endognath. 



The second maxilla (1'late XXIX., Fig. 2'') has two small and slender 

 protognathal lobes, the anterior of which is much the longer. The endo- 



