139 
The fluviatile Oligochaeta are very rare. They belong to 
orms of which the genera, and in many cases the species also, 
lave an almost world-wide distribution. The marine and littoral 
ipecies, too, although partly new, do not show any well-marked 
listinctions from known species. As before stated, the principal 
geographical interest is attached to the terrestrial forms, but 
from these must first be separated those species which have been 
ntroduced by man. Of these latter, two, viz., Helodrilus caligi- 
nosus (Sav.) and Microscolex dubius (Fletch.) are the commonest 
Earthworms in South-West Australia, having been found in 
almost every locality visited. 
The endemic earthworms (34 new species) all belong to the 
family Megascolecidae and are remarkable for their small size, 
only a few species, viz., M egascolex imparicystis, M. monostichus, 
M. harveyensis, Plutellus strelitzi and P. woodwardi being of even 
moderate dimensions. 
The Geographical Relations and Geographical History 
of the Country. — These need not bp gone into here, as the 
conclusions arrived at are almost ider a cal with those mentioned 
in the first abstract* ; it must, however, be stated that after 
more exact examination the generic districts were found to be 
even more restricted than at first supposed. For example, the 
new genus Woodwax dia, which has been separated from the larger 
genus Notoscolex, is confined to a very small district, including 
Lion Mill, Subiaco, and Jarrahdale. 
Systematic List of Species from South-Western Australia : — 
Family NAIDIDAE. 
Pristina longiseta (Ehrbg.). — Brunswick, in a stream ; a widely- 
distributed species. 
Family TUBIFICIDAE. 
Clitellio abjornssoni, n. sp. — Rottnest, Albany, on the beach and 
in the sea as far as a depth of 9 m. (4 to 5 fathoms). The 
original monograph includes a discussion of the genera 
Clitellio and Rhizodrilus. 
Family ENCHYTRAEIDAE. 
Enchytraeus albidus (Henle.). — Albany, Geraldton (?), in the sea 
at a depth of 5^-9 m. (3 to 5 fathoms), on the beach (?). A 
widely distributed species. Perhaps imported by man. 
Genus Michaelsena. — Description of the arrangement of the setae 
in this genus and discussion of its affinities (allied to Frideri- 
cia ?). 
Michaelsena principissae, n. sp. — Albany, on the beach. Re- 
lationship of this species to M. paucispina 
(Eisen), M. unisetosa (Ferronn), and M. macro- 
chaeta (Pierant). 
Tnis Journal, Vol. II., Part 5. 
