2 T. V. HODGSON. 



Richardson. We were certainly unfortunate in not capturing a greater numV)er of 

 specimens. The small species belonging to the Janiridse, ^lunnidas and their 

 allies were very abundant and much time was spent in going over the sponge 

 debris, which was invarialjly the predominent feature in the shallow water fauna ; 

 they were taken for the most part by the D - net inside the 25 - fathom 

 line, and it is among these forms that the chief interest in the collection 

 lies. Seven .species, mostly assigned to new genera, have their eyes on enormous 

 peduncles. This, I believe, to be an entirely new feature. In dealing with 

 the Isopoda of the French Antarctic Expedition (12) Miss Uichard-son has introduced 

 two .species possessing this interesting feature to science ; the ' Discovery ' adds five 

 more, and among those specimens the ocular peduncle is even more slender and 

 elontrated. Under these circumstances can the Isopoda be regarded as universally 

 .sessile-eyed ? l"p to the present it has been so, and the Munnidaj have been 

 considered to be on the way to a different state of things. Among that family it is a 

 very moot point whether the eye can be said to be on a peduncle at all, as the cephalic 

 process is so large, but now these new southern forms show a long and slender peduncle 

 quite on a par with those of the podophthalnious Crustacea, wliich reduces the value of 

 a hitherto characteristic feature of this group to a niiuimuni, and the existence of a 

 joint has only to be proved to destroy it altogether. 



I here append a list, as far as I have been al)le to ascertain, of all Isopoda hitherto 

 obtained in the Antarctic regions ; several of these are as yet little more than mere 

 names to me. Those taken by the ' Discovery ' are marked with *. The total number 

 is one hundred and eleven, of which twenty-nine belong exclusively to the Antarctic, 

 seven more belong to both the Arctic and sub-Antarctic regions, and the remaining 

 seventy-five exclusively to the latter. As stated in my Report on the ' Di.scovery ' 

 Pycnogonida, I take the northern limit (jf the sub-Antarctic region to be the mean 

 annual isotherm of the surface water of 45° F., as defined by Buchan in the 

 concluding volume of the ' Challenger ' Reports, and the latitude GO'' S. as tlie boundary 

 between the sub-Antarctic and the Antarctic regions proper. I have, however, gone a 

 step further in dealing with some Pycnogonids from the Magellan Straits. I then 

 found it desirable to define a Magellan region, and therefore divided the entire 

 Antarctic into three provinces, naming them from their points of attack, it being 

 obvious that any visit to the South Polar regions would be made from the land masses 

 to which these names refer, Kerguelen, of course, standing for Africa. 



In accordance with the above I have noted the province from which each species 

 has been taken : — 



Australasian province between long. 100° E. and long. 130° W. 

 Kerguelen province lietween long. 100° E. and long. 20° W. 

 Magellan prrjvincc between long. 20° W. and long. 1.30° W. 



It may reasonably be objected that these boundaries arc purely artificial, and that 



