FROU THE AUSTRALIAN TERTIAEIE5. 



413 



Sind, has a similar character. There is now no doubt that the suc- 

 cession of the species of Salenia has been from the Cretaceous age 

 through the Eocene and Miocene to the present day, and that the 

 definitions of the species indicate that the principal generic characters 

 prevail in all. But it does not appear, from the consideration of the 

 species of Mollusca, or of the other species of Echinoidea which are 

 found in the same deposits as Salenia tertiaria, Tate, S. Pellati, 

 Cott.*, and S. Blanfordi, Dune. & Sladen t, that they were dwellers 

 in deep water. Certainly the same kind of evidence, when applied in 

 the instance of the Cretaceous forms of the genus, does not show 

 that they lived under the same conditions as those species which 

 have been dredged up from great depths. It would be more correct 

 to say that there is no evidence to show that the ancient species had 

 the same bathymetrical range as the recent forms. A. Agassiz, in 

 his report on the ' Challenger ' Echini, 1881, p. 209, explains that the 

 range of the species as a group is from 60 to 1850 fathoms, and it 

 may be reasonably assumed that the Tertiary species did not exist 

 at the extreme depths, but that they and the Mollusca which were 

 found associated with them were dwellers in a less depth than 500 

 lathoms. 



5. PsAMMECHixrs AYoodsi, Laube, 1869, Sitzungsb. Akad. "Wiss. 



Wien, Bd. lix. p, 185 ; R. Etheridge, jun., Quart. Journ. Geol. 

 Soc. 1875, vol. xxxi. p. 447. 



The specimens of this Psammechinus in the collection of the 

 Geological Society are fairly preserved, except in the apical system. 

 They are small and tall, and certainly have triple compound plates 

 formed upon the true Echinus principle ; but although Mr. 

 Etheridge, jun., has figured the apical system of a specimen in the 

 Bianford collection now in the British Museum, which is similar to 

 that of a common species, it will be observed that the Australian 

 forms are somewhat unusual and aberrant. 



6. Ortholophtjs lixeatus, Dune. 



Temnechinus lineatus, Dune. Quart. Journ. Geol. Soc. vol. xxxiii. 

 1877, p. 46. 



This form has given a vast amount of trouble in its classification, 

 and it has been necessary to define a new genus for its reception. 

 When the species was included by me in the genii s Temnechinus, 

 Forbes, the morphology of the plates of that genus and of Ternno- 

 pleurus was not known ; but subsequently a considerable number of 

 Echinoidea, which had been placed under Temnopleurus, Agass., by 

 d'Archiac and Haime, were studied by Mr. Percy Sladen and 

 myself ±. A few years ago § the morphology of the coronal plates of 



* Rev. et Mag. de Zool. ser. 2, t. xii. p. 222 (1860). Eocene, 

 t Pal. Ind. ser. xiv. Foss. Ech. W. Sind, pt. 2, p. 28 (1882). 

 X Pal. Ind. ser. xiv. Foss. Ech. Sind, pt. 2, p. 36 (1882). Foss. Ech. Kach, 

 p. 54 (1883). 



§ Journ. Linn. Soc, Zool. 1882, xvi. p. 447 : also A. Agassiz, Report on 

 ' Blake ' Echini, 1883, p. 37. 



Q.J.G.S. Xo. 171. 2f 



