CKUSTACEA OP NEW ZEALAND. 187 



the perseon the depth is about equal to the breadth, the ventral surface being more or 

 less flat, so that here the body is semi-cylindrical ; in the pleon the segments (except the 

 first and sixth) have the pleura much produced below into smooth, flat, thin plates 

 protecting the pleopoda ou either side. 



The surface of the body is smooth throughout, with a few setae scattered here and there 

 either singly or in small tufts, cliielly on the dorsal surface. 



Eead (I'l. XVI. fig. 1). The dorsal surface is convex, curving downward in front, 

 making the outline of the head in lateral view roughly subtriangular. The anterior 

 margin, as seen from above, is concave behind the bases of the antennse. A depressed 

 line on the side of the head toward the posterior end runs down more or less parallel 

 with the posterior margin and runs out into the inferior margin ; it does not extend over 

 the dorsal surface of the head. Behiud the base of the lower autennte there is a slio-ht 

 cleft in the front margin, and behind this a slight depression on the surface which 

 extends backward a little distance and then turns downward. The inferior maro-iu of 

 the head is nearly straight. In the dried specimen there is no trace of the eyes, the 

 exoskeletou being apparently continuous over the place where the eyes would be situated 

 if they were present. 



Ferceon (PI. XYI. fig. 1). The first segment is only half as long as the second ; it widens 

 a little iuieriorly and has the antero-iuferior angle somewhat produced, so that the front 

 margin slopes forward and brings the lower part of the segment very close up to the 

 head. The inferior margin is slightly convex and not hollowed for the reception of 

 the epimeron, which appears to be ankylosed to the segment, the suture being indistinct. 

 The second, third, and fourth segments are all similar and subequal, and of the same 

 length at the inferior margin as on the dorsal surface. The inferior margin is nearly 

 straight, but slightly concave anteriorly for the reception of the shallow epimeron ; the 

 anterior angle produced into a rounded knob, tipped with a few setae ; the posterior auo-le 

 rounded, with a few setse in the third and fourth segments. The fifth segment is some- 

 what shorter than the fourth ; the anterior angle of the inferior margin is rounded and 

 bears a few setae, Avhile the rest of the inferior margin is deeply emargiuate to receive the 

 triangular epimeron ; the sixth and seventh segments are similar to the fifth, but each is 

 shorter than the preceding one. 



Fleoii (PI. XVI. fig. 1). The first segment is shorter than the last segment of the 

 perseon, but of nearly the same depth ; the inferior margin is rounded off at both angles 

 and bears about G to 8 minute spinules scattered along the margin. The second, third, 

 and fourth segments are subequal and somewhat longer than the first ; they have their 

 pleura produced inferiorly into large, thin plates, considerably deeper than the respective 

 segments. The pleuron of each segment has the anterior angle of the inferior margin 

 rounded ; posteriorly the pleuron is slightly produced so as to overlap that of the 

 succeeding segment ; that of the second segment is also produced anteriorly as far as the 

 anterior margin of the first segment, fitting in below its small pleuron; the posterior 

 angles are slightly produced and usually bear a few minute spinules. The fifth segment 

 is nearly as long as the three preceding; its pleuron has the posterior angle well 

 rounded, tiie posterior margin and part of the inferior margin being sparingly supplied 

 with spinules. 



SECONB SElllES. — ZOOLOGY, VOL. VI. 25 



