448 ONISCID.E. 



ISOPODA. ONISCID^. 



NORMALIA. 



Genus— PHILOSCIA. (Latreille.) 

 ZIA. {Koch.) 



Generic character. Ovate, sub-depressed. Cephalon rounded, 

 not lobed. Inner antennte minute, conical. Outer antennae 

 with cylindric joints, eight-jointed. Coxfe of sixth segment 

 of pleon obsolete ; first to fifth, narrow, linear. Uropoda 

 entirely exserted ; basal portion quadrilateral, transverse. 

 Rami elongate, pointed at tip ; outer terminating in a bundle 

 of setse ; inner more slender, and extending beyond the 

 middle of the outer ramus. 



It is a curious circumstance that the animals of this 

 genus, common as they are, and well described by 

 Latreille and Zaddach, should have been unknown to 

 Brandt, LerebouUet, and Milne Edwards, who have 

 affirmed that the genus ought to be reunited to Oniscus, 

 whereas it is in fact more nearly allied in several respects 

 to Ligia. The typical species appears to have been 

 figured by Koch under the name of Ligia melanocephala, 

 which in his generic table he subsequently altered into 

 the generic name of Zia, giving, however, fifteen joints 

 to the antennae, the flagellum being represented as com- 

 posed of ten articulations. 



The species are glossy, with the body flattened, and 

 the head destitute of lateral or frontal lobes. " The 

 inferior border of the frontal ring of the head is nearly 

 straight across ; the transverse suture well marked, 

 nearly on a level with the superior margin of the ex- 

 ternal antennae, its superior margin curved, raised, and 

 passing slightly beyond the frontal line of the cephalic 



