LEFEBVRE ON MANTIS. 67 



of the thorax, &c, — he established nine genera ; which, added 

 to the two already in existence, raised to the number of eleven 

 the divisions which these Orthoptera now range under 

 naturally and conveniently. 



Still there was one species which had escaped the attention 

 of this indefatigable and clever entomologist, who would, on 

 no occasion, establish new genera except with the specimens 

 before him, and who did not venture to form an opinion of a 

 species, and a fortiori make a new genus from any figure, 

 however correctly drawn. 



It was in the account of the Expedition to Egypt, (PI. 2, 

 Orthop.) that the insects of the genus now under consideration 

 were figured for the first time. M. Audouin had been very 

 desirous of furnishing the descriptions to these plates, but, as 

 he informed me, in the absence of every kind of specimens, 

 and having only the engravings, without either the insects or 

 the MSS., which, for thirty years, had lain buried in the pos- 

 session of M. Savigny, a he could only (as in the Arachnoida) 

 give a sketch of the tribes and groups to which the insects 

 described belonged ; and these Orthoptera were in like man- 

 ner included by him in the genus Mantis. I shall distinguish 

 them here under the name of Eremiaphila. 



When I was travelling in Egypt, in 1829 and 1830, under 

 the guidance of Dr. Pariset, (the head of the medical com- 

 mission appointed to make observations on the plague) an 

 excursion to the Oasis of Bahryeh b was deemed advisable by 

 him, partly for the analysis of the thermal waters it contains, 

 and partly for other medical investigations connected with his 

 mission. Drs. Lagasquie and Darcet were charged with the 

 chemical and medical observations, and Dr. Pariset allowed me 

 to avail myself of this invaluable opportunity of investigating 

 the natural history of this isle of the desert, which is yet 

 hardly known to us in a physiological point of view. 



We left the last traces of vegetation on the 27th of February, 

 to commit ourselves to these burning wastes ; and I beheld 

 one by one disappear, even the last vestige of animal life, with 

 the plants which might support it. After a day and a half's 

 journey, what was my surprise, when amongst the debris of 

 shells, of which I collected some magnificent specimens, (now in 

 the Museum,) amongst the nummulites which our dromedaries 

 * See Note I. at the end of this article. b See Note II. 



