Archbt. — The Marine Crayfish of Nexv Zealand. 



401 



The mandibles (fig. 2) appear to have 2 segments, and are short and 

 broad ; they are provided at the inner end with a pad of spines and a 

 3-toothed process. 



The 1st maxillae are biramose, but iinsegmented, and each ramus bears 

 a couple of deeply set spines. The 2nd maxillae are separated from the other 

 mouth parts and from each other ; they are long, almost straight pro- 

 cesses, with the convex inner margin bearing a spine, and with 3 deeply 

 set spines at the end. 



Fig. 1. — Naupliosoma larva of Jasus lalandii (M.-Edw. 

 Pig. 2. — Mandible of naupliosoma larva. 



X26. 



The 1st maxiUipedes are rudimentary, but there is a distinct segment 

 in this region. The 2nd and 3rd maxiUipedes are similar in shape, but the 

 3rd are much the larger ; they have 5 segments, with spines at the end of 

 the last. 



The 1st and 2nd peraeopods are broader and stronger than the 3rd 

 maxiUipedes, and do not, as yet, bear setae, the swimming being performed, 

 as before mentioned, by the setae on the antennae. The 3rd peraeopod 

 differs from the others by having only a rudimentary exopod ; the 4th 

 p raeopo ' is rudmentary, and the 5th is not developed at all. In the 

 figure the peraeopods are shown extended, whereas in life they are carried 

 closely folded under the thorax. 



