154 HORN EXPEDITION — SUMMARY. 



Lowur Steppes .•uid is also rocurdud (its original locality) fioni tlic Iloutmaii's 

 Abrohlos off the coast of Western Australia, and (3) Thersih's fodinalis the most 

 abundant land shell. 



^\'llilst such species as Microphyura /iciiiitiai/sa, Aiii^asella sctigera, Thersitcs 

 aJiOikiaiia, S/i'//i{i{vn/ iiiterioris, Fnpa nioorcaiia and Siiccinca iiiterioris are 

 (listriljutcd largely amongst the ranges of tin; Higher Steppes, others sucii as 

 Endodonia (Cini/la, E. planorbiiUna^ E/ai/iiiiti/iiia retiiiodes, Augasc/Ia ciizvi^a, 

 ,4. uu////ir/cc-(i//(!, .7. a/n\^c>\'ns, Chloritii s,/iia)iiHlosa, Tliersitcs ;^randiliibi:i-iHlaia^ 

 Tlicrsiics ivattti, Lipanis spciiccri and Pupa ficulnca are very sporadic in occurrence, 

 most of them Ixung so far as yet known limited to one single locality and often 

 occurring in small colonies in a space not more than a few yards square. 



As Professor Tate says, "Like the truly endemic plants, the land snails live on 

 the southern escarpments of the elevated land or in the deeply-shadowed gorges of 

 the same and occur in very restricted areas, sometimes as one colony only, or if in 

 mor(^, then usually widely separated from one another." 



With regartl to the water-mollusca, Mchiiiia vt'iiiis/ii/a, Bitliiiiia aiisiralis, 

 Buliiiiis pcchnvsiis, Corbicitla siiblcEvigata, antl Unio stnarti are oidy recordetl 

 from the Lower Stejipes ; Me/aiiia ba/o/uieiisis, Bi/liii/is tcxturatiis and Isidorclla 

 navcoinbl t.)^i:\xv in both the Lower and the Higher SLepi)es, \v\\Wt. Liinuica vinosd, 

 Buliiius dispar, PlanDrbis fragilis, Ancyhis aitslra/iciis and Spluo'iiiin transIucidKin 

 are recordcjd only from the Higher Steppes. 



Crustacea. — In the Crustacea the Phyllopoda are repi'escntcd by nine species 

 lielonging to live genera,, the Macroura and the Urachyura l)y one species each. 



Up till tlie time of the E.xpedition no species of Apus was cleHniLely recordeil 

 from Australia though its existence has been mentioned by Messrs. Sanger and 

 Lanckroft, Ijut as no description was given it was impossible to determine whether 

 this species belonged to the genus Apus or its close ally Lepidurus, which has long 

 been known from the continent and from Tasmania and New Zealand. 



The species Apus aiistraliciisis was first secured near Charlotte Waters in the 

 Centre, and its distribution is now known to extend over the interior of the 

 colonies of New South Wales and Queensland and into West Australia. Just as 

 Apus is characteristic of tiie interior and west, so Lepidurus, whicli is not found 

 there, is characteristic of the easter'n coast and of Tasmania and New Zealand. 

 The New Zealand, New South Wal(;s, Victorian, Tasmanian and (with perhaps 



