32 THE VOYAGE OF H.M.S. CHALLENGER. 



Echinanthus, and others, which are in our clay still so characteristic of the i^.ustralian 

 region. 



But there was a time when the peculiar Australian genera of the present day extended 

 far to the westward. Laube ^ figures a most interesting species under the name of Chry- 

 somelon vicentice and Chrysomelon pictum, of which most certainly the nearest allies are not, 

 as he suggQ^ts, Melonites, hwt the Australian generic types Holopneustes and Amhlypneustes. 

 In addition to the above the species with decided Pacific afiinities are Sismondia planulata 

 closely allied to Laganum honani and Clypeaster hreunigii to Laganum decagonum, while 

 Scutella tenera rej)resents the American Tertiary element together with a number of 

 species of Clypeaster proper and of Echinanthus, which, as is well known, obtained a great 

 development in the Tertiaries of Southern Europe, as well as Echinolampas, Hemiaster 

 proper, and Schizaster of a more or less Hemiasteroid facies. From what has preceded, it 

 is evident that, in making these comparisons between the fossils of a district with those still 

 found living at great depths in other areas, we at once find how impossible it is to establish 

 a synchronism from the comparison of identical species in distant formations. Palaeon- 

 tologists have frequently enough felt the futility of attempting to establish merely upon 

 palseontological evidence the synchronism between distant beds supposed to belong to the 

 same formation. This brings us, it seems to me, face to face with the identical problems 

 we are attempting to solve to-day, when stating that the typical Austrahan Echinids 

 belong to the present Fauna. What have we to support that assertion ? — A single species 

 of Fsammechinus, a few Triplechinidae, a few Clypeastroids and Spatangoids, and a 

 couple of species of Cidaris. 



Now, what has taken place in Australia ? AVe may picture to ourselves in other 

 times and places the gradual extinction of the Cidaridse and of the Clypeastroids ; the total 

 disappearance of species stiU found fossil, but now no longer living, which connect them 

 with the Tertiary period, and only the types of Psammechinus, Goniocidaris, and a few 

 types characteristic of the Indo-Pacific realm, with the present Fauna, whUe the typical 

 form Amhlypneustes is most e\adently descended directly from the Chalk, and the wider 

 geographical distribution in space which we have begun to trace among the fossils was 

 also accompanied by a greater persistency in time ; as dilferent a condition of things as 

 possible from the state of things of the present day. 



From the comparative lists of Corals from the Tertiaries of the West Indies made by 

 Duncan, it is very evident that the affinities of by far the greater number are with the 

 recent coral Fauna of the Pacific, the Indian Ocean, and the Eed Sea, with the Miocene 

 period of the Australian, Java, Indian, and European Tertiaries. AVhat trace there is of 

 the connection claimed by Duncan to have existed between South Europe and the West 

 Indian Islands I fail to see. That this connection of South Europe existed with the 



' Dr Gustav C. Laiibe, Ein Beitrag zur Kenntniss der Echinodermen des Vicentinischen TertiSigebietes. Denk ; 

 <l. Kais. Akad. d. Wiss. Wien., xxix., 18fi8. 



