HORN EXPF.niTION — BOTANY. 135 



few species ; in a soutli-west. direction tliis species extends to Harrow Rans^e. The 

 same remarks apply equally well to Mii-liclia o.xyclada, Jh/r/onia pfllyz\;^a, /sofropis, 

 spp., Leschenajiltia divnricata and StypJwUa Mi/c/icl/i. In this connection the 

 gcnna /acksfl?iia is conspicuously absent from the Larapintine basin. 



CoHc/usioits. — The distribution of the constituent elements of the Larapintine 

 ilora and their exotei'ic relationships, taken in conjunction with the physioj^raphic 

 changes that have taken place within the area, lead to the conclusions that : — 



1. The Larapintine table-land was isolated, except perhaps in a northerly 

 direction, during the deposition of the marine sediments constituting the IJolling 

 Downs system (Upper Cretaceous). 



2. The marine sulnnergence was replaced by a lacustrine area during tiie 

 deposition of the Desert Sandstone (Supi'a Cretaceous). 



3. A cosmopolitan flora prevailed at this period, which continued into Paleocene 

 times. 



4. The area occupied by the lacustrine area of the Desert Sandstone period 

 was somewliat reduced, yet high pluvial conditions continued into Pliocene times. 



f). In Post-Pliocene times a high state of desiccation was reached, which has 

 continued till to-day. The cosmopolitan ilora became lai-gely extinct, and its 

 place occupied l)y an Oriental inniiigration, more especially over the previously- 

 submerged areas. 



4. Previous Explorations. 



The first botanical exploration of the Larapintine region was l)y J. Macdouall 

 Stuart, who collected during his traverses from the Finke lliver to the INTcDonnell 

 Range in 18G0-G2. The plants were determined by Raron von Mueller, and their 

 enumeration published as an appendix to the "Journals of J. McD. Stuart," 

 London, 18G4. Of the tifty-two species catalogued, thirty-two were gathered 

 within the area which foi'ms the suV)ject of this report ; seven of them weie scien- 

 tifically unknown till descrilied by F. von Mueller in \o!s. ii. and iii. of the 

 " Fragmenta Phyt. Aust." 



Ten years later Ernest Giles geographically explored the Larapintine region 

 to the westward of the Finke River, and made extensive botanical collections. A 

 list of the species, fur'nished by IJaron von Mueller, was published as an appendix 

 to Mr. E. Giles' "Geographic Travels in Central Australia," 1872-74 (.Melliourne, 



