478 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 
species being called Dipus canadensis. The article was immediately copied 
into Tilloch’s Philosophical Magazine,* with reproduction of the colored 
plates by which it was illustrated. These same figures, representing the ani- 
mal in activity and in repose, were also copied by Dr. G. Shaw in his General 
Zodlogy in 1801 (plate 161), and the species became established upon this 
name “canadensis”, already the third one bestowed upon it. 
The fourth designation of the species, “‘Dipus americanus”, 1s derived 
from Barton; it really anticipated Davies's ‘‘canadensis”, though not in date 
of publication. In the year 1795, Prof. B. 5. Barton communicated an account 
of the species to the American Philosophical Society, which body published 
it in the fourth volume of their Transactions,+ bearing date 1799. In this 
article, the learned and ingenious author named a species, Dipus americanus, 
on page 115; he discussed at length its probable relationships with Dipus 
hudsonius of Zimmermann, and with “ Mus longipes”, coming to the conclu- 
sion it was distinct; and finished with an interesting account of its habits. 
Some years later, the same writer presented to the society a second papert 
on the species, devoted to further consideration of the creature’s habits, 
with special reference to its torpidity or hibernation. These excellent 
accounts of Professor Barton’s have probably not been excelled in accuracy 
of detail. 
We thus see how the species came to be generally known by three dif- 
ferent names, 
hudsonius, canadensis, and labradorius—to say nothing of the 
“Mus longipes”. Later authors are nearly equally divided in their use of 
these terms, but Audsonius clearly has priority. Coming to later synonyms, 
I find a quotation of a Gerbillus sylvaticus, a name said to have been proposed 
by 8S. L. Mitehill, without accompanying description; and also of a Meriones 
nemoralis, attributed to Is. Geoffroy St. Hilaire. These references I have not 
been able to verify. 
After treating of ‘ Gerbillus” canadensis, in his Fauna Americana, in 
825, apparently from fair acquaintance with the animal, Dr. R. Harlan, in 
839,§ described specimens from Philadelphia as a new species under the 
* An Account of the Jumping Mouse of Canada, Dipus canadensis. By T.Davies. < Tilloch’s Phil. 
Mag. i, Aug. 1792, pp. 285-287, pl. viii, figs. (colored) 1,2. (From Tr. Linn. Soe. iv, 1798, pp. 155-157.) 
tSome account of an American species of Dipus or Jerboa. < Trans. Amer. Philos. Soc. iv, No. 
xii, pp. 114-124, with pl. not numbered opp. p. 124. “Read” 1795; vol. dated 1799. 
tSupplement to the account of the Dipus americanus, in the IV. Vol. of the Transactions of the 
Society. See No. XII. < Trans. Amer. Philos. Soe. vi, 1804, pp. 143, 144. Read Dec. 1803; vol. dated 1804, 
§ On a New Species of Meriones. < Proc. Zoél. Soe. Lond. vii, Jan. 1839, p. 1. Subsequent to the 
collection of the anthor’s papers published by Lydia R. Bailey, under the title ef “Medical and Physical 
Researches” (8vo, Philada, 1835). 
