40 
T. V. HODGSON. 
The three posterior appendages of the mesosome are not very long, the 
proportions of the joints being 11. 6. 4. 4. 8. 7. The basis bears four or five stout 
spinous processes externally, the number and strength of these vary ; the ischium only 
bears short setae with which it is fairly well covered ; the merus and two following 
joints bear along the ventral surface a series of stout spines, in addition to small setae 
irregularly scattered. The dactylus is thinly covered with fine, small setae and has a 
stout terminal claw and a small accessory. 
A number of specimens of this species were taken in Winter Quarters inside the 
25-fathom line, and one was taken in 125 fathoms. The average length of the body 
is 22 mm. Most of the specimens are females and, as one expects in members of 
this genus, the anterior part of the mesosome is considerably enlarged. Also the 
development of the spines is much increased, and those on the mesosome from which 
one of the specific characters are derived become comparatively enormous. There is 
also an indication of a stronger lateral spine on the third or fused segment of the 
metasome. 
None of the females bear young, many of them have ova ; these were captured in 
October and February. The males have the dorso-lateral spines very much less 
prominent, and the body is uniformly cylindrical throughout. 
The oostegites of the females number four pairs, and the most posterior pair are 
supported by a stout spine from the epimeron of the fourth segment of the mesosome 
which almost reaches to the mid-ventral line, this also bears subsidiary spines. 
The species w T as described from a single small though apparently fully developed 
female taken off Franklin Island by the ‘ Southern Cross ’ Expedition. With that 
individual w T ere associated three very small and obviously immature specimens. 
Knowing that the spinous armature increases with age, and more especially so among 
the females, I declined to regard these as other than possible juveniles of this species. 
This turns out to be correct, but the complete absence of large spines in the 
male led me to regard them as another species which was to have received the name 
of A. australis. It was not till I found that all my specimens of A. franklini were 
females and all those of A. australis were males that I discovered the error. It is 
absurd to suppose that during a residence of two years, and capturing these animals 
one or two at a time, only one sex of each of two species should be taken. The 
figures will show the differences between the two sexes, the most remarkable being 
o o 
the complete absence of the larger spines. 
The foregoing description of A. franklini is based entirely on the females. 
In the male the four anterior segments of the mesosome are practically smooth, 
though rather tuberculated laterally, the first of them bears an epimeral spine. They 
progressively increase in length, the fourth being half as long again as the first. 
The segments of the metasome, though fused, are more distinct than in the 
female ; two dorso-lateral spines, larger than the rest of those covering the urosome, 
are sometimes present. 
