134 15R. C. CHILTON ON THE 



Eyes of moderate size, with fifteen to twenty ocelli. Antennae as long as the head and 

 first three segments of mesosome minutely setose throughout; second and third joint 

 suhequal, fourth longer, fifth twice as long as the fourth and longer than the flagellum ; 

 joints of flagellum increasing in length distally, and the third followed hy a styliform 

 process or hristle, fully as long as the first joint and dividing at the end into a compact 

 pencil of setae. Legs fairly long and very spinous, inci-easing considerahly in length 

 posteriorly. Eirst two pairs of pleopoda with the opercular plates partially l)ilohed. 

 Uropoda wdth the outer joint much longer and stouter than the inner, which arises only 

 a little anterior to it and reaches to the middle of the outer, both setose and bearing one 

 or two longer setae at the end. 



Colour brown, with wavy stripes of white on each side the median line and often 

 with two lateral rows of whitish patches, the number and size of the white markings 

 varying greatly. 



Lemjth about 10 mm. 



Habitat. — Very common throughout the whole of New Zealand. 



Remarks. — I have had some little hesitation in referring it to the genus Oniscus as 

 now restricted, for it differs distinctly from the definitions of that genus as given both 

 by Budde-Lund and by Sars in that the mandibles do not bear so many " penicils " 

 behind the cutting-part ; I find only one on each mandible, though another one or 

 sometimes two are situated on the setose membi-anaccous lappet just internal to the 

 cutting-edge. According to Budde-Lund Oniscus should have four or five penicils. 

 Moreover, the anterior segments of the mesosome have the posterior margin straight 

 instead of deeply sinu.ate, and the last segment is broader and less produced than is usual 

 in Oniscus. Budde-Lund (p. 206) suggests that the species under consideration may 

 lielong to Philoscia, and it certainly agrees with that genus in the mandibles and in the 

 posterior margins of the segments of the mesosome, but it differs from that genus in 

 possessing well-marked though small lateral lobes on the cephalon, and in having the 

 epimera of the mesosome of fair size, and those of the third to fifth segments of metasome 

 well marked. On the whole I prefer to leave the species under Oniscus, for though 

 allied genera are plentiful enough I cannot at present find one that will suit it better. 



The species is widely distributed throughout New Zealand, and presents considerable 

 variation in colour, breadth, and compactness of the body prominence of the front and 

 lateral lobes, &c. I have some specimens collected by Mr. W. W. Smith on limestone 

 rocks at Albuy, Canterbui'y, which in colour resemble the variety marnwratus of 

 Porcellio scaber, the general surface being very light yellow, marked with somevrhat 

 sparsely-scattered black dots and markings ; the small spines on the surface are more 

 marked than in typical specimens, the front is less produced, and the lateral lobes of the 

 cephalon are very small and inconspicuous, while the joints of the flagellum of the 

 antenna? are more equal in length. In other respects they resemble Oniscus punctatus 

 so closely that I prefer, for the present at any rate, to consider them merely as a variety 

 of that species, for which I propose the name marmoratus. 



The specimens from Mount Wellington, Tasmania, referred to this species by 



