46 NOTES ON TASMANIAN CRUSTACEA, ETC. 



The most interesting of my finds is certainly the Schizopod 

 shrimp ( dnaspis) found in pools at the top of Mt. Wellington. 

 How an animal of such conspicious size should have hitherto 

 escaped the observation of collectors, occurring as it does in 

 a locality which res5idents, as well as visitors, to Hobart visit 

 in numbers every season, is only another proof of the small 

 amount of attention which has hitherto been paid to this 

 section of the Tasmanian fauna. 



This animal is, I think, one of the most remarkable Crus- 

 taceans found of late years. How and when its ancestors 

 reached its present habitat is one of those questions which 

 we have no present means even of guessing at. Its nearest 

 allies— and even they are very distantly related — appear to 

 be among the Euphausiidse, a deep sea group of Schizopods. 

 But the whole structure of the animal has become so pro- 

 foundly modified from that of all known Thoracostraca, that 

 I think we must assign it a very high antiquity. To take 

 only two of its most prominent characteristics, it has com- 

 pletely lost the shield or carapace so distinctive of all other 

 animals of the order Thoracostraca, and no doubt in asso- 

 ciation with this its gills have become plate-like and project 

 externally along the sides of the thorax. The loss of the 

 carapace is the feature which has suggested the name Anasjois 

 to me. In respect to this feature, and also in its gills, the 

 animal resembles an Amphipod, the resemblance being, how- 

 ever, purely external and having no importance. It ie this 

 feature again which suggests the great antiquity of the form, 

 for among all the Thoracostraca the carapace appears at an 

 extremely early stage of the development of the individual, 

 and is present in all the sub-orders. In the Euphausiidae 

 the young animal is hatched as a Nauplius with a large well- 

 developed carapace. At what stage of its development 

 Anaspis loses its carapace, or has already in the course of its 

 evolutionary history lost it, is a question which I am unable 

 at present to solve ; meanwhile I think it advisable to create 

 a new family Auaspidse (Tribe Schizopoda) for its reception. 

 The occurrence of fresh-water Amphipoda of the genus 

 Niphargus is another point of great interest. N. montanus 

 seems common enough in the smaller pools and among the 

 swampy ground on the top of Mt. Wellington. I did not find it 

 in the large pools with Anaspis; the latter would, ^^erhaps, 

 exterminate it in such open localities. I collected N. mortoni 

 originally in a small rill at an elevation of only 200 or 30O 

 feet above high-water mark, at Franklin on the Huon, and 

 was at first under the impression that it might prove only a 

 transitional form between a littoral and a fresh-water species. 

 But it appears to be abundant in the streams coming down 

 the seaward side of Mt. Wellington at elevations of 2000 feet 



