136 Macrteay Memoria Vouume. 
which is relatively longer and narrower than in 7. mzxor, wants the terminal 
dilatation, and is provided with a median sharp-pointed spine, usually retracted, so as 
to be contained within the lumen of the introvert, but everted when the cirrus is 
protruded. In addition the introvert is armed with a very large number of small 
spinules, which bristle out when the terminal spine is protruded. The lobes of the 
vitelline glands are comparatively few and large. The ducts of the prostate glands 
are very large, and are dilated where they open into the basal bulb of the penis, so as 
to form a sort of reservoir for the secretion. 
This species occurs along with 7: mzxor on the surface of Astacopsis bicarinatus, 
both in New South Wales and Victoria. The differences mentioned above, though 
not very extreme, were found quite constant throughout the large number of 
specimens examined. The two species differ widely also, as already mentioned, in the 
nature of the eggs and the mode of their attachment. They are not stalked in 7: 
Dendyi and are attached most commonly to the inner wall of the branchial chambers, 
sometimes to the bases of the gills. 
T. Dendyz is often found in considerable numbers in the branchial cavities of the 
erayfish. 
5. TEMNOCEPHALA QuaDRIcoRNIS. Plate xu. fig. 10, and Plate xiv. fig. 4. 
Temnocephala quadricornis, Haswell, lc. p. 284, pl. xx. fig. 3. 
This, the only Tasmanian species I have seen, is at least equal in size to 7. 
fasciata. It is of a dark brown colour, finely mottled. Its most striking external 
feature is the presence of only four tentacles, the median one (or two) present in the 
other species being replaced by a short, broad dorsi-ventrally compressed lobe with a 
convex anterior border. The sucker is very distinctly radiated, and is relatively 
rather larger than in 7: fasctata. The internal organisation is similar to that of the 
last-named species, but there are fewer constrictions in the intestine (seven or eight); 
both pairs of testes are situated further back—the anterior, which is round and 
undivided, being behind the middle of the intestine, and the posterior, which is 
rather larger and bilobed, being situated somewhat behind the genital cloaca; the 
introvert of the cirrus is smaller, and its spines, instead of being nearly uniform in size, 
and shape or gradually increasing in length from without inwards, are arranged in 
three distinct sets: a set of many short acute spines, which closely beset the outer 
part and bristle outwards when it is everted; a small number of blade-like, pointed 
spines a good many times the length of those of the first set; and a limited number of 
slender spines intermediate in length between those of the first two sets and slightly 
hooked at the ends. The last two sets must be extended like the median spine of 7; 
Dendy when the cirrus is fully protruded. 7° guadricornts occurs on the surface 
