CEUSTACEA OF NEW ZEALAND. 239 



numerous slender setae ; the convex outer margin of the plate is also supplied with 

 many very fine seta? like those found on some parts of the maxillae. The meros 

 bears about six setae on the outer margin towards the extremity and numerous setae 

 on its inner margin. The carpus is similarly supplied with setae. The propodos 

 is about two-thirds as long as the Ciirpus ; it bears three or four setae on the outer 

 margin, and numerous long ones on the inner margin and on the surface near to it ; 

 on the upper surface of the propodos (fig. 16) is a longitudinal row of about twelve 

 set;e, extending right along the centre, with a few others more or less irregularly placed ; 

 the outer extremity of the propodos at the base of the dactylos is produced into a small 

 rounded lobe. The dactylos is long and slender, being about two-thirds the length of 

 the propodos ; both margins bear five or six setae ; it narrows somewhat abruptly at the 

 extremity, and bears a stout spine or nail. The normal form of the dactylos is shown 

 in fig. 16 ; that shown in fig. 15 is evidently deformed, and was found on the right side 

 of the same maxillipede. 



The foregoing descriptions of the mouth-parts have been taken from a large-sized 

 male specimen. The mouth-parts of the female differ in several respects and are 

 described belo^^, where some remarks on the probable changes that take place in the 

 mouth-parts during the development of the male will also be found. 



The^rs^ gnathopod (PI. XXIII. fig. 1) is very large and strong, much larger than the 

 second. The coxa (side-plate) is nearly as deep as its segments and is rhomboidal in outline, 

 projecting strongly forward ; it bears a very minute seta at tlic anterior end of the lower 

 margin, and one or two at the hinder end. The basos is long, somewhat curved at the 

 base ; the anterior surface is grooved to receive the propodos when the limb is bent back 

 at rest. The ischium is short and of the usual form. The meros is short, not much 

 longer than the ischium ; the anterior surface is rounded and bears a number of setae 

 more or less regularly arranged in three transverse rows. The carpus is very short, 

 subtriangular, produced below on the outer side into a small rounded lobe, densely 

 tipped with setae ; when seen from the inside (fig. 2) the carpus appears quite rect- 

 angular. The propodos is very large, much longer than the basos ; the upper margin is 

 regularly curved and without setae, except one or two very small ones at the base of the 

 dactylos ; the basal part of the lower margin forms a rounded lobe densely covered with 

 numerous setae arranged in five transverse rows ; the palm occupies the whole length of 

 the lower margin with the exception of this lobe ; it appears rather broad, the outer 

 edge bearing ten small tufts of rather long setae, each tuft containing from two to four 

 setae. When seen from the inside (fig. 2) the end of the palm, against which the 

 dactylos impinges, appeal's to be slightly concave ; the end is defined by three long 

 spines ; roimd the edge of the hollow on the inside is a row of about seven shorter 

 spines, and near them are some simple setae more or less regularly arranged in tufts. The 

 inner edge of the palm is rather convex, and, except towards the proximal end of the 

 palm, it extends beyond the inner edge ; it is minutely serrate and fringed with a few 

 small setae, and near it is a longitudinal series of about twelve short oblique rows of 

 long setae, each containing from five to ten setae. The dactylos is large and strong, 

 slightly curved, and with a few very minute setae on the concave margin, but these do 



