Ilymoiiosoina ileprcssum, Jacquinot and Lucas. 147 



liaving been dredged on the Greymouth bar in 20 fathoms ; 

 very probably they had been collected by ilr. Ilelm-i at the 

 same time as the s|)('cimen in his own collection. 



I have notes on these specimens, made at the time, stating 

 that they appear to agree well with the original description 

 and figures by Jacquinot and Lucas, with which I had com- 

 pared them, and that Miers's remarks as to the figure are not 

 altogether correct, but that the front is really " dentiform,'' 

 /. e. tooth-like, and narrowing to its extremity, instead of 

 being " of equal width throughout,'' and that there could 

 scarcely be said to be ''a small tooth outside the eyes" 

 either in the figure or in the specimens. In my MS. notes I 

 also mentioned the tact that the terminal joints of the last 

 four pairs of legs were fringed with hairs and looked as if 

 they were u-ed as swimming-organs, like the legs of the 

 water-boatmen (NotonecliilaB). 



T saw no further specimens of this species till December 

 1905, when IMr. Marriner brouglit me a dried specimen 

 found at Sumner, Canterbury, precisely like those already 

 referred to. 



This specimen is a male, while the original description and 

 figure were drawn up from a female specimen, so that I can 

 add to it the few points in whicli the male differs from the 

 female. 



The well-marked fringe of long hairs on the distal joints of 

 the last four pairs of legs is worthy of notice, for this, com- 

 bined with the flat depressed carapace and the very long legs, 

 shows, I think, that the crab is cajiable of swimming. 

 Jacquinol's specimen is said to have been taken under stones 

 at low tide on the shores of the Auckland Islands ; the two 

 in Mr. Drew's collection were dredged on Greymouth bar at 

 20 fathoms ; I have no definite information as to the circum- 

 stances under which the other two s])ecimen3 which I have 

 seen were taken, but there is nothing in these rccoitls incon- 

 sistent with the power of swimming. Most of the ordinary 

 swimiuing-crabs iiave the last pair of legs specially flattened 

 for the purpose, but probably many other crabs possess some 

 ])ower of progression by swimming evmi without special 

 modification of the legs ; this is certainly the case with the 

 young of Petrolisthes elongatus, Milne- Ivlwards, just hatched 

 out from the last Zojca-form, as 1 know from personal observa- 

 tion that it can swim with considerable agility. 



The whole of the Hymenosomidaj of New Zealaiul require 

 careful revision, and until that is done the generic position of 

 this species must remain an open question ; in the meantime, 

 however, I give a new description of the species, which, with 



10* 



