JACULTJS. 
301 
JACULIDiE. 
JACULUS. 
Jaculus, Erxleben, Syst. Reg. Anim. 1777, p. 404. 
Dipus, Gmel. Linn. Syst. Nat. 1788, p. 157 (partim). 
Hind legs greatly elongated, with only three toes. 
JJentition: i. m. | = 16. 
Incisors grooved. 
On the Egyptian Jerboas in general. 
The young Swedish naturalist and traveller, Frederick Hasselquist, arrived in Egypt 
from Smyrna in May 1750, and two months later visited the Pyramids of Gizeh\ and 
on that occasion observed a jerboa, of which he appears to have obtained specimens, as 
he, in the very same month, sent a description of it in Latin to Linnaeus who com¬ 
municated it to the Academy of Science at IJpsala. Hasselquist called this jerboa 
“ Mus cegyptius pedibus posticis longissimis.” 
In the following September he again visited the Pyramids and observed this 
animal for the second time. He left Egypt in the end of March 1751, but when in 
Smyrna in November of the same year he forwarded a paper in Swedish to the 
Stockholm Academy of Science 3, describing it again under the popular name of the 
Egyptian Mountain Rat, and gave a figure of it. In the description of this jerboa in the 
Latin edition of his ‘ Travels ’ Hasselquist mentions that his “ Mus cegyptius 6cc. ” was 
known to the French as the “ Rat de montagne,” and in his Swedish paper he says no 
Swedish name could be better than a translation of the French appellation. It is 
probable that the two papers refer to one and the same species, which in both 
descriptions he characterized as Mus pedibus posticis longissimisJ 
The ‘ Iter Palsestinum ’ was not published until 1757, and Linnaeus took a great deal 
of trouble wdth its publication. He says he digested the work in the best manner he 
could, ranged everything under its proper tribe, added names to plants and animals, 
altered the technical terms and manner of writing without changing in the least the 
author’s meaning. He had the work corrected at the press and personally inspected 
its publication, all this being necessary as Dr. Hasselquist had died. Linneeus says : — 
^ ‘ Voyages and Travels in tlie Levant,’ Engl. ed. 1766, p. 66. 
^ Op. cit. pp. 421, 427. 
3 Acta Stockh. 1752, vol. xiii. pp. 123-4, fig. 1. 
^ Iter Falsest. 1749-1752 (Stockh. 1757), p. 200. 
