
16 RECORDS OF THE S.A. MUSEUM 
Sars’ families are well defined. In this family, while the typical forms show a 
first antenna with reduced segmentation and the fourth endopod reduced or absent, 
in some forms this leg is normal and the first antenna has a greater number of 
segments and does not show the fusion of segments between the second and eighth 
so characteristic of the majority of the genera. 
These few exceptional genera nevertheless show the expanded body with well- 
developed epimera and have the female genital segment greatly expanded in its 
anterior half. These two features are, therefore, regarded as characteristic of the 
family, and those genera which do not show the reduction in the first antenna and 
fourth leg, but are otherwise typical, are regarded as intermediate between the 
Asterocheridae and Dyspontiidae. 
Famity ASTEROCHERIDAE Giesbrecht sens. str. 
syn. Ascomyzontidae Sars, 1915, p. 83. 
Sars (op. cit., p. 85) discards Boeck’s name Asterocheres in favor of Thorell’s 
Ascomyzon, although he admits it has priority, because ‘‘the species of this genus 
are by no means exclusively parasites of Asterids’’. Boeck’s name must, however, 
stand on rules of priority and has been accepted by recent authors. 
Thorell (1859) used the name Ascomyzontidae to designate a family which 
is apparently equivalent to the Asterocheridae of Giesbrecht (1899) since the lat- 
ter author had previously (1895, 1897) used Thorell’s name, and in 1899 (p. 67) 
place this name as a synonym of his new name. 
Giesbrecht divided his family into sub-families, which Sars (1915) raised to 
family status, and further subdivided, but reverted to the name Ascomyzontidae, 
used in a restricted sense, equivalent to Giesbrecht’s sub-family Asterocherinae 
from which he removed the genus Acontiophorus as the type of a new family. 
As stated above, I have followed Sars’ classification, but since the genus 
Ascomyzon no longer exists it cannot be used for the family name. I have, there- 
fore, substituted Giesbrecht’s Asterocheridae, used in the restricted sense equiva- 
lent to Sars’ Ascomyzontidae. 
One genus of this family was found here and a new genus, which approaches 
Dermatomyzon, is described. 
AUSTRALOMYZON gen. nov. 
The genus is defined by the following combination of characters: Body com- 
paratively slender, with little or no development of epimeral plates; urosome 4- 
segmented in the female, 5-segmented in the male; first antenna with the segmen- 
tation of the proximal region distinct; second antenna 4-segmented, with a re- 
duced exopod attached to the second segment; oral cone produced into a siphon, 
reaching to the first legs; rami of the first four pairs of legs 3-sezmented. 
The genus is intermediate between Dermatomyzon and Rhynchomyzon, re- 
sembling the latter in general appearance, having posterior projections on the 
metasome segments, and the former in having similar projections on the urosome 
segments. It resembles both of these genera in the segmentation of the urosome 
and differs from both in the presence of a well developed siphon. 
AUSTRALOMYZON TYPICUS sp. nov. 
Occurrence. IX, 1 male; XI, 2 females. 
Female. Length 1:20 mm. Anterior body ovoid, rounded in front, with a 
small rostrum directed postero-ventrally. The first segment is fused with the 
head, the second and third have postero-lateral projections, and the fourth seg- 
