
JOHNSTON AND EDMONDS—AUSTRALIAN ACANTHOCEPHALA 359 
or straw coloured, The largest male is 170 mm. long and 1-0 mm, wide in the 
broadest part; it consists of about 200 ‘‘segments,’’ while most of the females are 
about 230 mm, long and 1-4 mm. wide near the middle of the worm where the 
breadih is greatest. The colleetion also contains two very large females, each of 
abort 280 segments, one measuring 65 em, long and 3:9 mm. wide and the other 
68 em. long and 3-6 mm. wide. The specimens are probably the longest of all known 
echinorhynchs, 
The proboscis is cylindrical and small when compared with the size of the 
worm, Its maximum dimensios are: wale, length 0:52 mm., breadth 0-31 mm.; 
and female, length 0-74 mm., breadth 0-42 mm, It is armed with numerous hooks 
which fall into two groups, The anterior third of the proboscis is beset. with 
12 spiral rows of 5 hooks each and the posterior two-thirds with 12 spiral rows 
of 14-16 smaller hooks which are spiniform and less regularly placed near the neck 
recion. Most of the hooks hear rooting processes, the shape of which we have not 
heen able to determine satisfactorily. Tn the case of ihe anterior hooks it seems 
to be a three-pronged process (fig. 13 and 14), All the hooks arise from a slight 
swelling of the epidermis (fig. 15 and 16), The body of both sexes is smooth. 
The region of the animal immediately behind the proboscis is slightly swollen 
and contains the receptaculim and lemnisei. The pseudo-segmentation in this 
region in both sexes and in the posterior portion of the male is not very well marked 
externally, The proboseis receptaculum consists of two parts, an anterior portion 
Which arises at the junction of the two groups of proboscis hooks and which is very 
thin ventrally (fig. 17), and a posterior sac-like portion with a single thicl 
continuous wall (fig, 24). Mhisele fibres pass from. within the proboscis to enter 
the hody cavity of the pavasite at the junction of these two parts of the 
receptaculum. A similar type of proboscis sheath has been deseribed by Meyer 
(1982, 181) in the ease of Empodius otidiy (Mieseher). An oval brain is situated 
ventrally in the anterior portion of the proboscis. The lemnisci are much larger 
than the receptacnlum, The lacunar system is well developed and consists of one 
long channel from which arise transversely, smaller eirvular collecting vessels. 
Male System. Two elongate elliptical testes of approximately equal size are 
situated well towatds the posterior part of the worm and their maximum dimensions 
are: length 2-5 mm., and breadth 0°65 mm-_ Hight elliptical cement glands, 
although closely pressed together, appear to be arranged in four pairs. There are 
two narrow cement ducts and a pyriform Saefftigen's pouch, The male opening 
is terminal. 
Female System. The female complex is small m comparison with the size 
of the animal. Its structure is shown in fig. 19, The typical uterine bell of an 
echinorhynch seems to be either collapsed or lacking in most of our female 
specimens. A structure of very thin tissue which possibly acts as a uterine bell, 
