Miscellaneous, 437 



Tlic animal ^vhicli constitutes the subject of this memoir must 

 therefore, it seems to me, interest naturahsts in a very particular 

 manner ; for it had hitherto escaped their researches, and it differs 

 so much from all the great Linnean genera that, in order to bring it 

 under the existing classifications, it is necessary to establish for it in 

 the order Rodentia, not only a new genus, but even a special family. 

 I propose to eive it the name o( Lophiomi/s Imhausii (L'Institut, 

 tome XXXV. p. 4G, Feb. G, 18G7; Annals, May 18G7, p. 372). 



This little mammal lived for nearly two years in the Garden of 

 Acclimatization in the Bois de Boulogne. I am indebted to the 

 kindness of M. Alb. Geoffroy Saint-Iiilaire for being able to under- 

 take this investigation, and 1 eagerly take this opportunity to thank 

 him publicly for the numerous services of this kind which he is 

 constantly rendering me. 



Lophiomys Imhausii is of the size of a small rabbit ; but its aspect 

 is very different ; for it is provided with a long tufted tail, and the 

 hairs of its back are erected in such a manner as to form a sort of 

 longitudinal mane. The hairs of the flanks are likewise very long, 

 but pendent ; hence they are separated from the mane by a furrow, 

 tbe bottom of which is occupied by hairs of a very singular aspect : 

 they are of a greyish-fulvous colour, lying down upon the skin, thick 

 and flattened : microscopic examination shows that their structure is 

 spongy, and that the epidermic sheath which surrounds them con- 

 stitutes an actual network with irregular meshes, in the midst of 

 which longitudinal fibres are arranged. The remainder of the fur is 

 mixed black and white. 



The inner digit of the hind feet is well detached from the others, 

 and by opposing itself to these can form a true prehensile hand, of 

 which the animal makes use to seize forcibly the objects upon which 

 it climbs. 



The most important characters of Lophiomys Imhausii are fur- 

 nished by its osseous framework, and more particularly by its head. 

 The upper surface of this is entirely covered with miliary granula- 

 tions, arranged with perfect regularity and symmetry. No mammal 

 presents an analogous arrangement. Behind the orbits the head is 

 extremely wide ; but this is not due to the development of the cra- 

 nial case, which is in reahty narrower than in most rodents : it re- 

 sults from the ossification of the aponeuroses of the crotaphital 

 muscles, which extend over the temporal fossae in such a manner as 

 to unite with the bones of the check and complete the orbital frame 

 behind. I know of no example in the Mammalia of a similar mode 

 of organization; and we find nothing analogous to it except in certain 

 reptiles, and especially in Testudo caretta. 



The dentary system differs less from that seen in various rodents, 

 and enables us to ascertain that it is to the MuridcB that Lophiomys 

 presents the most resemblance. There are in each jaw a pair of in- 

 cisors, and three pairs of radiculatcd molars, of which the first con- 

 sists of three ridges separated from each other by deep grooves. 

 The genus Cricetus is the only one in which we find an arrangement 

 of the folds of enamel similar to that in Lophiomys. 



