INTRODUCTION. 



whether a passage-group of deposits (" Rhsetic ") are indicated by the evidence ; or, lastly, 

 whether these Plant-beds with Reptiles and Crustaceans indicate the terrestrial and 

 lacustrine conditions only of the early Mesozoic period. 



The jTiu'assic-like flora of Australia ^ and that of southern Africa have been hitherto 

 collected without affording any clear traces of the Estheria. The latter country, however, 

 has its probably Triassic reptiles, the Dicynodon and its many associates, imbedded with 

 this flora ; ^ so that the pecuhar association above indicated for India and North America 

 obtains there also. 



In pointing out these facts of the geological and geographical distribution of the fossil 

 Estheria, I merely touch upon the salient points of an interesting subject of research, for 

 the elucidation of which careful inquiry at home and abroad is still requisite. 



The known species of living Estheria are — 

 Estheria gigas, Hermann, sp. Baird, Proc. Zool. Freshwater pools, Strasburg {Hermann) ; brackish 



Soc, 1849, p. 87 {=Cyzicus Bravaisii, 

 Audouin, Annal. Soc. Entom. vi. 

 Bullet., p. IX, 1837; Isauracycladoides, 

 Joly, Annal. Science Nat., 2 s6r., 1842, 

 xvii, p. 293, pi. 7, 8, and 9 a (figs. I— 

 45) ; Estheria cycladoides, Lucas, Ex- 

 plor. Scieutif. Algeria, Crustaces, 81, 

 1845. 



Dahalacensis, Straus-DurcMeim. Mus. 

 Senckenb., ii, p. 119, pi. 7, figs. 1 — 

 16; Baird, Proc. Zool. Soc, 1849, 

 p. 89, Annulos. pi. 17, figs. 2—4. 



Melitensis, Baird. Proc. Zool. Soc, 

 1849, p. 88, Annulos. pi. 11, fig. 2. 



POLITA, Baird. lb., fig. 3. 



Brasiliensis, Baird. lb., p. 89, pi. 11, 

 fig. 4. 



DONACiFORMis, Baird. lb., fig. 5. 



BoYSii, Baird. lb., fig. 6. 



siMiLis, Baird. lb., fig. 7. 



TETRACERA, KrynicJci, sp. Bullet. Soc. 

 Imp. Nat. Moscou, ii, 1830, p. 176, 

 pi. 7, fig. 1 ; Baird, Proc. Zool. Soc, 

 1849, p. 90. 



Dallasii, Baird. Proc. Zool. Soc, 1852, 

 p. 30, Annulos. pi. 23, fig. 5. 



water marsh, Arzeu, near Oran, Africa (Bravais) ; 

 ditch filled with rain-water (in June), Toulouse 

 (Joly) ; Tunis (Frazer) ; Algeria (Lucas). 



Freshwater marshes of the Island of Dahalac, on 

 the coast of Abyssinia, in December (Biippell) ; 

 and in stagnant water, on the banks of the 

 Tigris, near Bagdad (fJ^. K. Loftus). 



Kain- water pool, Malta (Hennah) ; Sicily {Cuming). 



India (interior, N. E.), Boys. 

 Brazil {Sowerby). 



Abeyd (White Nile), Kordofan (Parreyss). 



India (interior, N. E.), Boys. 



India (interior, N. E.), Boys. 



Freshwater marsh (in May), near Charkow, Eussia, 



and at and near Moscow (Krynicki, Fischer, 



and de Laveau, 1817 — 29). 



Brazil (?) Dallas. 



' See M'Coy's paper, 'Ann. and Mag. Nat. Hist.,' vol. xx, p. 145, &c. ; and the Rev. W. B. Clarke's, 

 ' Quart. Journ. Geol. Soc, vol. xvii, p. 354. Labyrinthodont reptiles have not been wanting in Australia; 

 see Professor Huxley's paper on the Bothriceps Australis, ' Quart. Journ. Geol. Soc.,' vol xv, p. 647. 



2 Glossopteris, &c. ; ' Quart. Journ. Geol. Soc.,' vol. xvii, p. 329. Dicynodont remains have also been 

 discovered lately in connection with the coal-bearing strata of Bengal (ibid., p. 362, and Mem. Geol. Surv. 

 India, vol. iii, part 1.) 



