HALITHERIID& 223 



and if the intermediate links could be discovered might well be 

 looked upon as the ancestral forms from which the latter have been 

 derived, but at present the transitional conditions have not been 

 detected. So far as is yet known, when changes in the physical 

 conditions of the European seas rendered them unfitted to be the 

 habitation of Sirenians, the Halitherium type still prevailed. If the 

 existing Dugongs and Manatees are descended from it, their evolu- 

 tion must have taken place during the Pliocene and Pleistocene 

 epochs, the one in seas to the east, the other to the west of the 

 African continent, which has long formed a barrier to their inter- 

 communication. Halitherium remains have been found in many 

 parts of Germany, especially near Darmstadt, also in France, Italy 

 Belgium, Malta, etc. 

 Until a few years ago 

 none were known from 

 England, probably owing 

 to the absence of beds 

 of an age corresponding 

 to those in Avhich they 

 are found on the Eu- 

 ropean continent ; but Fio. 74. The penultimate and last right lower molars 

 a skull and several ^ ^ a ^ t ^ er ^ um fossile ; from the Miocene of the Continent. 

 , . (After De Blainville.) 



teeth have been detected 



among the rolled debris of which the Red Crag of Suffolk is partially 

 composed. The species are not yet satisfactorily characterised. 

 Some of them appear to have attained a larger size than the existing 

 Manatee or Dugong. One of these, from the Pliocene of Italy and 

 France, having but - molar teeth, has been separated generically 

 under the name of Felsinotherium by Capellini, by whom it has been 

 fully described ; but the difference in the number of the teeth 

 does not afford sufficient grounds for separation from HalitJierium. 

 Miosiren of the Belgian Miocene, differs in that the last upper 

 molar is the smallest, in place of the largest of the whole series 

 of teeth. 



Other fwms. Remains from the Pliocene of France described as 

 Prohalicore are regarded as indicating a Sirenian closely allied to 

 Halicore ; while a molar from the Tertiary of California has been 

 made the type of Desmotylus, which is likewise referred to the 

 Halicoridce. Dioplotherium, from the Phosphorites of South Carolina, 

 has been considered to connect Halicore with Halitherium, but even 

 its ordinal position is uncertain. 



A portion of a skull found in the Pliocene of Belgium has been 

 described as Crassitherium by Van Beneden ; and some compressed 

 teeth, somewhat similar to but larger than those of the Dugong, 

 discovered in the Miocene of the department of Lot-et-Garonne, 

 France, gave origin to the genus Rytiodus of E. Lartet. Of this 



