272 



NATURAL HISTORY. 



he felt the weapon, dragging the canoe after it round and round the bight until exhaxisted. Mr. 

 Alfred R. Wallace says the natives of the Amazon capture them alive, in strong nets, at the mouth 

 of the streams, and afterwards kill them by thrusting wooden plugs up their nostrils. The Manatee 

 has no milk-teeth, though when young there are two rudimentary incisors in each jaw, which after- 

 wards become covered in. Canines are entirely absent, and the molars vary in number from nine 

 to eleven in the upper and lower jaw on each side. Those in the upper series are three-rooted, in 

 the lower series two-rooted ; all the molars are broad, square-crowned, and with transverse ridging or 

 cusp structui'e like that of the Hippopotamus or partly like that of Mastodon. The molar series are 

 never simultaneously in place and use, those in front dropping out and making room for those behind. 



FOSSIL SIRENIA. The HALITHERIUM is the name given to certain fossil remains which have 

 been found in the Miocene strata of Germany and various other parts of Europe. These remains, 

 show that there may have been several species, but all are truly of a Sirenian character. The 

 fossil remains were intermediate, though possibly most closely allied to the Manatee, some of them 

 being slightly larger than this animal. The dentition is unusually interesting, inasmuch as there 

 appear to have been vertical successors ; anteriorly there are simple, cylindrical premolars, 

 and posteriorly larger, complex molars, while the somewhat bent-down upper jaw bore tusk- 

 like appendages. But the most peculiar and interesting point in connection with the Halitheria, 

 is that they were provided with rudiments of a hind limb, a thigh-bone some few inches in length 

 having been found by the late Professor Kaup, though curiously enough no further vestige of it 

 has since turned up. Judging from the almost complete skeletons obtained, and from comparison 

 with what we know of other Sirenia, the Halitherium must have closely resembled the living 

 Manatee, and possibly have lived in the lagoons and brackish waters of mid-Europe and elsewhere, 

 for in the Eocene and Miocene times these regions, now high and dry, formed watery areas in 

 communication with the ocean. 



Besides the foregoing, within the last few years our knowledge of Sirenoids has been considerably 

 augmented by the discovery of other fossil remains indicating several new genera. Prorastomus is 

 founded by Owen on a skull from "West Indian (doubtful) Tertiary strata. Crassitherium is applied 

 Van Beneden to vertebrae, and part of a skull from deposits near Antwerp. Felsinotherium (wit 

 but t| molar teeth) is a form described by Capellini, from Pliocene beds in Bologna. Pachyacanthu 

 found in strata in the neighbourhood of Vienna, Brandt supposed a Cetacean, but Van Benedei 

 regards it as a Sirenian. The Ehytiodus, of Lartet, is based on some fossil teeth bearing resemblanc 

 to those of the Dugong. Lastly comes (in the cast of a brain), the still more remarkable Eotherium 

 Owen, from the nummulitic Eocene of Egypt. Some of these fossils are of intense interest, fo 

 example, Prorastomus, the Tapir-like dentition of which is Incisors, |=| ; canines, t^ ; premolars, j 

 molars, ^ = 48. Very interesting also are Pachyacanthus, with possibly but six neck vertebrae, like 

 the Manatee ; and Halitherium, with its hind limb bones, and which also, along with Felsinotheriui. 

 foreshadows the molar pattern of Hippopotamus. Thus, taking these facts into consideration, 

 gether with many other structural peculiarities, Elephant-like and otherwise, and notwithstandii 

 that the Sirenia are aquatic and Whale-like, their structural relationship with the Proboscidea 

 Ungulata is not so far-fetched as at first sight might seem. But the gap is not yet bridged, and 

 until that is done the order Sirenia must be retained. 



JAMES MUKIE. 



MOUNTED SKELETON OF HALITHERIUM, IN THE HEIDELBERG UNIVERSITY MUSEUM* 



