CRUSTACEA OF NEW ZEALAND. 221 



three times as long as the peduncle, the inner branch rudimentary. Telson about half 

 as long as the terminal ui'opoda, narrowing slightly towards the extremity, which bears 

 two stout setae. 



Colour. White, semi-transparent. 



Length. About 8 mm. 



Habitat. Eyreton {Chilton) and Leeston [B. 31. Laing) ; Canterbury (in wells). 



Bemarks. Monicz says [78, p. 50] that this species differs little from Crangonyx 

 mbterraneus, Spence Bate. Bate's description of that species is, however, not sufiSciently 

 detailed to allow of a comparison of any value between the two. 



Detailed Description. 



Body (PI. XX. fig. 1.). The body is rather stout and deep, especially in the pleon. 

 The side-plates {coxce) are about half as deep as their respective segments, and are all 

 nearly equal in size. The head is as long as the first segment of the peraeon; segments 

 of per.Ton subequal, the posterior ones a little longer than those preceding them. First 

 three segments of the pleon subequal, a little longer than the last segment of the peraeon, 

 about twice as deep as long; inferior margin of each segment slightly convex and 

 furnished with four or five setae, arranged chiefly towards the anterior end ; last three 

 segments of the pleon very short. 



Eyes rudimentary, represented by two or three imperfect lenses without pigment. 



Upper antennce (figs. 2 & 3) considerably longer than the lower, about one-third 

 the length of the body ; peduncle slightly shorter than the flagellum ; first joint nearly 

 as long as the second and third together, upper margin straight and furnished with a 

 few minute spinules, lower surface grooved, bearing on the inner margin three stout 

 setae, the third being at the distal end, the outer margin without setae, winged, produced 

 downwards at the base, where it is slightly convex ; the second joint half as long again 

 as the third, a few fine setae on both upper and lower margins, those at the extremity 

 being longest and most numerous ; third joint similar to the second excejit in size. 

 Secondary apjwndage small, reaching to about the end of the second joint of the main 

 flagellum, consisting of two joints, the first as long as the first joint of the flagellum but 

 very slender, bearing ordinary setae ; the second small, bearing ordinary sette and a minute 

 olfactory cylinder at the extremity. Flagellum consisting of about thirteen joints, those 

 at the base nearly as broad as long, the others becoming more and more slender, each 

 joint from the second onwards bearing on the lower side of the distal extremity two 

 olfactory cylinders nearly as long as the succeeding joint, and two small tufts of ordinary 

 setae, one above, the other below. 



Loioer anteimce (fig. 4) having the first two joints very short, the gland-cone 

 arising from the second joint being very long and reaching nearly to the end of the 

 lower margin of the third joint ; third joint subquadrangular, with two stout setae in 

 the middle of the ujipcr margin and one long simple seta at the extremity of the lower 

 margin ; fourth joint only half as broad as the third, upper margin bearing a stout seta 

 near the base, followed by two or thi-ee slender setae, lower margin with three oblique 



29* 



