174 



Remarks. — This form was first described by Scopoli as early as in the 

 year 1763 under the name of Oniscus muscorum, and has subsequently been re- 

 corded by Fabricius, Brandt and Koch under other names; but now the specific 

 name proposed by Scopoli is generally adopted. In its external appearance, it 

 exhibits some ' resemblance to Ligidium hypnorum, but, on a closer examination, is 

 easily distinguished by the very different structure of the antennae and uropoda. 



Occurrence. — Two specimens of this form are preserved in our university 

 Museum, having been taken by the late Dr. Jensen, the one at Brevik, the other 

 at Langesund. I have not myself succeeded in finding it in the neighbourhood 

 of Christiania, nor in any other locality examined by me, and it would thus seem 

 to be very rare in this country. According to Mr. Budde-Lund, it is chiefly found 

 in forests, beneath moist leaves and moss. As might be supposed from its 

 slender and elongated legs, it is very rapid in its motions. 



Distribution. — Denmark, Prussia, Germany, Holland, Poland, Austria, 

 Britain, France, Spain, Italy, Algeria. 



Gen. 3. PlatyarthrUS, Brandt, 1833. 



Syn: Typhloniscus, Schobl. 



Generic Characters. — Body oval, much depressed, with the lateral parts 

 of the segments lamellarly expanded. Cephalon with well-marked projecting lateral 

 lobes. Metasome not abruptly contracted; last segment but slightly produced. 

 Eyes wholly absent. Antennae comparatively short and very strongly built, with 

 the joints of the peduncle flattened, flagellum only consisting of a single 

 joint. Oral parts resembling those in Philoscia. Legs short and thick, scarcely 

 increasing in length posteriorly. Opercular plates of pleopoda without air-cavities. 

 Uropoda rather produced, with the inner ramus originating far in front of the outer. 



Remarks. — This genus, established by Brandt, is chiefly characterised by 

 the total absence of eyes, the peculiar structure of the antennae, and the short 

 and thick legs. In the structure of the oral parts, it does not exhibit any es- 

 sential difference from that in other Oniscidse. The genus J yphloniscus of Schobl 

 is identical with Brandt's genus. We know of only 3 species belonging to this 

 genus, one of which will be described below. 



