262 



America. Such, however, was not the case with the two later synonyms 

 we have adduced. After treating of ^'- Gerhillus lahradorius'''' from fair 

 acquaintance in 1825, Dr. Harlan, in 1839, described specimens from 

 Philadelphia as a new species, under the designation of Meriones 

 microcephalus ; while, still later, Nova Scotian examples received from 

 Principal Dawson the appellation of Meriones acadicus. But the char- 

 acters adduced by both of these authors fail to indicate anything tangi- 

 ble ; and it is certain that if more than one species of Zaptis inhabits 

 ISTorth America, it remains to be discovered ; for the several queer ani- 

 mals of this kind indicated about the year 1817 by M. Bafiuesque, under 

 the names of Short-tailed, Long-tailed, Lion-tailed, Shrew-like, and Big- 

 eyed, are undoubtedly figments of that author's fertile imagination. We 

 quote these names with a query, together with the compiled accounts 

 that go with them, merely observing that, if they do not belong to Zapus 

 Jiudsonhis, they certainly belong nowhere else. To give credit where it 

 is due, however, we should not omit to add that, besides these five "new 

 species" of "Gerbillus", M. Kafinesque furnishes us with two others — 

 G. daviesii, which is merely another name for Davies's Dipus canadensis, 

 and GAudsonius, in presenting which last he has the credit of leading the 

 adoption of the specific name which has priority, and which must un- 

 questionably be adopted. Eecurring once again for a moment to the 

 earlier dates in the history of the species, we find a name Gerbillus syl- 

 vaticus, imposed by Mitchill, but without an accompanying description; 

 and still another, said to have been given by Isidore Geoffroy in the sev- 

 enth volume of the Dictionnaire Classique — Meriones nemoralis. 



It would appear, from the foregoing sketch of its history, that this 

 animal was already quite sufficiently named ; but this is only a consid- 

 eration of its specific appellations, without reference to the various gen- 

 eric terms by which it has been designated by authors, nearly all of 

 whom seem determined to make it out to be some kind of a Jerboa, 

 because of its powers of leaping. But nothing is more certain than that 

 it is not generically related to any of the BipodidK. It has usually been 

 placed at least in a subfamily Dipodimc. The family value of its char- 

 acters were only lately recognized, when, in 1872, Dr. Gill constituted a 

 family JacuUda\ overlooking the fact, as Professor Baird had also done^ 

 that the name Jacidus was pre-occcupied in another connection. 



