40 T. y. HODGSON. 



The three posterior appendages of the mesosonie are not very long, the 

 jjroportions of the joints being 11. G. 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-fathum 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 increa.sed, 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 cpimeron of the fourth segment of the mesosome 

 which almost reaches to the mid-ventral line, this also bears subsidiary spines. 



The species was described from a single small though apparently fully developed 

 female taken oft" Franklin Island by the ' Southern Cross ' Expedition. With that 

 individual were associated three very small and obviously immature specimens. 

 Knowing that the si)inous 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 -1. au'<tralis. 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 lime, only one sex of each of two species should be taken. The 

 figures will shcnv the ditterences between the two sexes, the most remarkable being 

 the complete absence of the larger spines. 



The foregoing description of A. franklini is ba.sed entirely on the females. 



In the male the four anterior segments (jf the mesosome are practically smooth, 

 though rather tuberculated laterally, the first of them bears an epinieral spine. They 

 progressively increase in length, the fourth being half as long again as the fii-st. 



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. 



