118 DK. C. CHILTON ON THK 



forms; the tuhercles l)oth on the body and on the antenu;e are particularly well marked, 

 and, in some specimens at any rate, the flagellum of the auteunge contains five joints. 



3. Trichonisctjs Thomsoni, Chilton. (PI. 13. fig. 1-) 



Philygria Thomsoni, Chilton, Trans. N. Z. Tnst. xviii. p. 159, pi. v. figs. 1-6 (1886). 



Specific description. — Oblong oval, greatest breadth fully half the length, fairly 

 convex, surface quite smooth. Cephalon short, transverse, more than twice as broad as 

 long ; lateral lobes small, not visible in dorsal view, front slightly convex, a slight 

 transverse depression a little anterior to the eyes, and an oblique depression starting 

 near the median line between the eyes and extending backwards and outwards. Epiraera 

 largely developed, those of the first segment of mesosome produced anteriorly into 

 rounded lobes enclosing fully one-half of the cephalon, those of the second and third 

 segments with the posterioi- angles rectangular, those of the fourth to seventh segments 

 recurved and acuminate in progressive degree, those of the seventh i^eaching as far back 

 as the posterior border of the fourth segment of metasome. Metasome much narrower 

 than last segment of mesosome ; third, fourth and fifth segments with fairly-developed 

 but closely-appressed epimera ; last segment with posterior border straight and bearing 

 three or foiu' small setse. 



Anteunre slender, fourth joint of peduncle nearly as long as the fifth and slightly 

 broader, all covered with fine setae ; one or two longer ones at the extremities of the 

 second, third and fourth joints ; flagellum about as long as the last joint of peduncle, 

 of at least five joints ; articulations between the more distal joints very indistinct. 

 Legs rather long, increasing considerably in length posteriorly, very spiny. Dactylar 

 seta large and well developed, dividing into two branches, each of which subdivides in 

 many fine hairs. Uropoda rather long, about two-thirds the length of metasome ; outer 

 ramus much the stouter, elongate, conical in outline ; inner three-fourths the length of 

 the outer, cylindrical, tapering very gradually, i)oth eadiug in a few settle. 



Colour a light brown, with the greater part of the body covered with markings of a 

 much darker brown, sometimes nearly black ; legs with irregular alternate markings of 

 light and dark brown. 



Length about 7 mm. 



Habitat. — Widely distributed over the whole of the South Island. 



Memarks. — This species can usually be recognised by the wide body with greatly 

 developed epimera, by the smooth, almost shining appearance of the dorsal surface, and 

 by the five joints in the flagellum of the antenna. In smaller specimens, however, the 

 epimera are not so much expanded, and the articulation in the flagellum may be A^ery 

 indistinct and identification is the more difficult. Though a tru^e Trichoniscus in the 

 mouth-parts, metasome, &c., the general outline is more suggestive of an Oniscus or 

 Forcellis. 



The mouth-parts closely resemble those of the preceding species. The pleopoda also 

 are very similar, except that in the second pleopod the endopodite is more elongate in 

 the female, and in the male the penial appendage formed by it is of a slightly different 

 shape. 



