The significance of these animals may be indicated more clearly by the following statement. If the history of _Elephas antiquus_ be critically traced, this animal appears first in a somewhat hazy atmosphere, viz. that of the transition period between Pliocene and Pleistocene times. It is a more primitive form of elephant than the Mammoth. Indeed, Gaudry[27] (1888) placed it in a directly ancestral relation to the last-mentioned elephant. And though the two were contemporary for a space, yet _Elephas antiquus_ was the first to disappear. Moreover this elephant has much more definite associations with the southern group of mammals than has the Mammoth. Its presence is therefore indicative of the considerable antiquity of the surrounding deposits, provided always that the latter be contemporaneous with it. With regard to the Rhinoceros, the species _R. megarhinus_ and _R. etruscus_ have been found in definitely Pliocene strata. The former (_R. megarhinus_) seems to have appeared earliest (at Montpellier), whereas the Etruscan form owes its name to the late Pliocene formations of the Val d'Arno, in which it was originally discovered. The third species (_R. merckii_) is somewhat later, but of similar age to _Elephas antiquus_, with which it constantly appears. It is remarkable that the _R. etruscus_, though not the earliest to appear, seems yet to have become extinct before the older _R. megarhinus_. The latter was contemporary with _R. merckii_, though it did not persist so long as that species. With regard to the three alluvial deposits, the Rhinoceros provides a means of distinction not indicated by the elephantine representative, and the presence of _R. etruscus_ is a test for very ancient deposits. From what has been stated above, it follows that of the three localities the Mauer Sands have the more ancient facies, and it is significant that here also the human form proves to be furthest removed from modern men. But the other localities are not clearly differentiated, save that the Taubach strata are perhaps the more recent of the two. Coming next to the 'peculiar' animals; the _Ursus arvernensis_ of Mauer is almost as distinctively 'Pliocene' as its associate, _Rhinoceros etruscus_. The Taubach strata have yielded nothing comparable to these, nor to the Trogontherium (or Mimomys) of the high-level terrace gravel. These animals are also strongly suggestive of the Pliocene fauna. To sum up, it will be found that the evidence of the Elephant is to the effect that these alluvial deposits are of early Pleistocene age. It leads to the expectation that the fauna in general will have a 'southern,' as contrasted with an 'arctic' aspect. From the study of the Rhinoceros it appears that the Mauer Sands are probably the most ancient in order of time, that the strata of Taubach are the latest of the three and that _Elephas antiquus_ will occur there (as indeed it does).