478 Proceedings of Royal Society of Edinburgh. [sess. 
The inaxillulae (fig. 19, mxl.) are simple in form, with a few 
minute bristles at the tip or their inner faces ; the arm (fig. 19, hr.) 
which supports the maxillula is bent and irregularly furcate in 
shape. It is connected by a ligament (fig. 19, lig.) with the outer 
framework of the maxillula, this being itself continuous with the 
inner chitinous rod of the maxilla (fig. 19, rh. int.), as explained 
by Folsom (1899) for Orchesella. 
The maxillae (fig. 19, mx.) are of the typical Collembolan form ; 
the palp, however, is remarkable on account of the production of 
its tip into a tongue-shaped process bearing four bristles, and the 
excessive development of the long proximal bristle and its papilla 
(fig. 19, pa.). 
Distributional Notes. 
As mentioned in the introduction to this paper, the existence of 
identical or of nearly allied species of Collembola on widely 
separated areas may be regarded as strong evidence for ancient 
land connections between those areas. Many recent writers on 
zoological geography have expressed belief in a former extension 
of the Antarctic continent, wide enough to connect with America, 
Africa, and Australia. A full discussion of the problem has 
recently been given in Ortmann’s valuable paper (1904, pp. 310- 
324, with map, pi. xxxix.) on the Tertiary invertebrate fauna 
of Patagonia, and there can be no doubt that the trend of modern 
speculation is against the doctrine of the permanence through past 
ages of the great ocean basins of the present day, as upheld in 
the classical writings of Darwin and Wallace. Hutton, who 
many years ago suggested the Antarctic continent as a former 
means of communication between Australia and Patagonia, and 
subsequently withdrew the hypothesis in favour of a trans-Pacific 
continent, has now re-affirmed his former belief (1905), laying 
special stress on the Collembola of South Victoria Land as 
evidence for the former connection of that remote region with the 
northern continents. 
From the facts established in the present paper, further support 
for the ancient extension of Antarctica may be readily drawn. 
The existence of the genus Cryptopygus and of the species 
Isotoma octo-oculata on the South Orkneys as well as on Danco 
