26 BULLETIN OF THE 



Avail of the efferent passages from the branchial chambers and on a plane above 

 the bases of the antenna?, so that the efferent passages terminate in the space 

 between the upturned edges of the squamiform processes of the inner sides of 

 the basal segments of the antennulse and just beneath the short two-spined 

 rostrum. In the middle of the slightly raised and regularly arcuate posterior 

 edge of the epistoine there is a slight elevation with a tuft of hairs. The 

 anterior part of the endostome is on a plane somewhat above the plane of the 

 epistome, but the space below is filled by the soft and fleshy labrum which 

 projects considerably below the raised posterior edge of the epistome. 



The mandibles (PI. IV. fig. 2) are wholly without molar areas and with 

 crowns expanded into very broad and thin lamella? serrated along the cut- 

 ting edges with about fourteen acutely triangular teeth, of which one at the 

 anterior angle and one in the middle are much larger and more prominent than 

 the others. The palpus (fig. 2 a ) is short, but composed of three segments, of 

 which the proximal is very small ; the second is fully as long as the terminal, 

 and expanded distally, and the terminal about three and a half times as long 

 as broad, and densely setose along the anterior edge and ventral side. 



The lobes of the metastome (fig. 2) are very narrow and widely separated. 

 The two lobes of the first maxilla (fig. 3) are very much as described and 

 figured by Willemoes-Suhn in Willemoesia leptoclactyla, the two lobes being very 

 slender and strongly incurved, and the anterior the larger and with a slight 

 elevation covered with a dense tuft of hairs on the outside near the base. 



The second maxilla (fig. 4) has two small and slender protognathal lobes, 

 of which the anterior is very much the larger. The scaphognath is very large, 

 and with the posterior portion very broad and evenly rounded in outline pos- 

 teriorly, while the anterior portion is much narrower, and reaches forward 

 nearly to the base of the antenna. The endognath is apparently represented 

 by a short and truncate lobe at the base of the anterior lobe of the protognath. 



The first maxillipeds (PI. IV. figs. 5, 5 a , 5 b ) are greatly elongated and 

 peculiarly modified. The exopodal lamella (/, fig. 5 a ) is long and very broad, 

 projects farther back into the branchial passage than the scaphognath, and 

 terminates anteriorly in a small triangular lobe (g) ; while the exopod reaches 

 forward considerably in front of the epistome, where its terminal lobes are 

 somewhat upturned and help to enclose the efferent branchial passage. The 

 proximal lobe of the protopod (a, figs. 5, 5 a ) is triangular and densely seti- 

 gerous along the edges, while the distal lobe (a') is elongated, and bears the 

 endopod and the peculiarly modified exopod, which lie together, and at nearly 

 a right angle with the protopod. The endopod (b, figs. 5, 5 b ) is slender, 

 somewhat triquetral, reaches nearly to the bases of the terminal lobes of the 

 exopod, is densely hairy along the edges, is divided near the middle by an im- 

 perfect articulation, and lies above and close along the inner edge of the exopod. 

 The exopod (c, figs. 5, 5 b ) is lamellar, very broad, concave dorsally, divided by 

 several sutures, as shown in the figure, curved inward almost to the mesial 

 line, and encloses the broad efferent passage ventrally and anteriorly. The 

 terminal portion of the exopod is divided into two lobes (d, e, figs. 5, 5 b ), which 



