89 



NOTES ON SOME SPECIES OF THE ISOPOD FAMILY 



SPH/EROMID/E FROM SOUTHERN AUSTRALIAN SEAS, 



PART III. 



By W. H. Baker, F.L.S. 



[Read October 12, 1911.] 



Plates XXII. and XXIII. 



The present paper deals with only two species, but these 

 are of more than ordinary interest. The first, though here 

 given as a distinct species, may, however, as a variety be 

 useful in elucidating the very attractive genus Amphoroidea. 

 The other, besides belonging to the division Platyhranchiata? y 

 presents some unique features of its own. 



Family SPH^EROMID^. 



Subfamily Sph^romin^e. 



Group Eubranchiat^;. 



Genus Amphoroidea. 



Amphoroidea elegans, n. sp. PI. xxii. 



The body is broadly ovate with the epimera spread out 

 laterally. The dorsal surface is very obscurely tuberculate 

 medianly, glabrous, and covered with minute dots. The 

 colour in nature is green, being found among green seaweed. 



The head is only a little broader than long, trilobed 

 anteriorly. The eyes are lateral, situated in little angles 

 just anterior to the postero-lateral angles of the head. 



The antero-lateral angles of the first thoracic segment 

 reach to the level of the eyes, leaving the anterior portion of 

 the head free. The remaining thoracic segments do not differ 

 much from each other in length. 



The anterior portion of the abdomen has a well-marked 

 first segment not showing lateral expansions; the following 

 segment is marked by two sutural lines on each side and has 

 large epimeral expansions a little produced backwards. The 

 posterior portion of the abdomen is domelike, with slightly 

 incurved sides and a shallow lunate posterior notch. 



The lamellar expansions of the first antennular joints 

 are rather short and slightly excavate above. There is a very 

 narrow lenticular hiatus between each contiguous margin. 

 The flagellum has 13 joints. 



The antennal flagellum has 20 joints, gradually increasing 

 in length, the whole reaching to near the posterior angle of 

 the third thoracic segment. 



