SCHIZOPODA, STOMATOPODA, AND NON-ANTARCTIC ISOPODA. 889 



Genus Idotea, Fabricius. 



Idotea metallica, Bosc. 

 Scotia. 



Fifteen specimens belonging to this species were found among the collec- 

 tions submitted to me, without any note as to the locality of their 

 capture. I suspect they were taken among the Gulf weed, through which 

 the Scotia passed between 22nd June and 30th June 1904. 



Station 482, Saldanha Bay, Cape Colony, May 1904.— Two. 



Family Astacillid^. 



Genus Ayitarcturus, zur Strassen. 



Antarcturus ornatus, sp. nov. (Plate, fig. 5.) 

 Scotia. 



Station 482, Saldanha Bay, Cape Colony, May 1904. — One female, 7 mm. 



Plate, fig. 5, gives a general idea of the form of this species and shows its most 

 characteristic feature, namely, its ornamentation or armature of short, stiff" bristles on 

 all the segments of the body. 



The head and the first three segments of the thorax equal together the length of 

 the large middle segment. The last three segments of the thorax are widely separated. 

 The metasome has tv/o segments partially marked off with transverse sutures. 



The setse are found on the dorsal surface of the animal, on all the segments, as well 

 as on the head and metasome. The surface of the body is irregular, roughened, and 

 microscopically spinulose, but there are not any distinct tubercles. The first three and 

 the last three segments of the mesosome are elevated dorsally when seen in lateral view, 

 and the setse are arranged in a broad band across this elevated part, and are most 

 numerous in the centre. The well-marked intervals between the last three segments 

 of the mesosome are devoid of setse. The middle segment of the body shows two 

 setigerous areas, a wide and broad anterior one and a narrow posterior one, separated 

 by a shallow depression devoid of setse. This is shown very well in lateral view. 

 Both the setigerous areas are elevated and roughened ; the non-setigerous band, smooth 

 and depressed. 



The eyes are moderately well developed and lateral. The superior antenna reaches 

 to the level of the distal end of the second joint of the peduncle of the inferior antenna. 

 The flagellum is equal in length to the last two joints of its peduncle and bears olfactory 

 filaments. 



The inferior antenna is two-thirds of the entire length of the animal from the 

 front of the head to the posterior end of the metasome. The fourth joint is equal in 



TRANS. ROY. SOC. EDIN., VOL. XLIX. PART IV. (NO. 16). 121 



