on the Fossil Insects of Aix in Provence. 253 
DIPTERA—continued. 
GENERA. Remarks. 
99 | Trichoceru, B. ..--..| 99] Very delicate. 
100 | Platyura, B, ....-...| 100 
HOUS Scraras Bea. losee se LOL 
102 | Scatops, B. & H....... 102 
103 | Penthetria, B. ......| 103 
104 | Dilophus, B. ....... -| 104 
105 | Anisopus, B. ....+.0: 105 
106 | Asilus, BW—H.?......| 106} Most likely part of an Asilus. 
107 | Empis, B.& H....... 107 
108 | Nemestrina, B. ......| 108 
109 | Xylophagus, B. ...... 109 
LOS) Oxyeera, BY <.... Sot) LIS) 
111 | Nemotelus, B. & H. ..| 111 
P20 | Aphritisy Bai. cw eees|| Lie 
TSs i Wipulast. tse. ce --| 113} A species allied to rivosa. 
In addition to the 113 genera given in the above tables, many 
others might easily be mentioned, and when all the specimens I 
collected reach this country the catalogue will be considerably in- 
creased. Amongst the Arachnida I have noticed an elongated 
species of Chelifer, and in the Myriapoda, Julus and Scolopendra ; 
in Insecta, there are about twenty genera added, hitherto I believe 
unnoticed by any individual; and from the numerous specimens 
in the hands of geologists and others, many more may yet be 
expected to occur. 
Before I attempt to describe the few species I have had figured, 
I must refer the Entomologist, for an account of the formation of 
Aix, to the writings of Murchison, Philips and Lyell. Some few 
remarks, derived from persons living on the spot, are also added. 
As my intended cicerone, in a visit to the fossil beds, was a 
medical man, and happened to be called away on more important 
matters than hunting for fossils, I had not during my stay another 
opportunity of visiting the spot myself, and therefore I was obliged 
to commit to paper the few observations I gleaned from my friends 
in conversation. 
The fossil insects are generally found in two laminated beds, 
each stratum rarely exceeding two inches in thickness, the stone 
itself looking like that which is commonly used in lithography; a 
third bed is also reported to have been discovered, but as it is not 
equally rich in specimens as the two uppermost beds, much atten- 
tion has not been bestowed upon it. Each of the above seams 
(if that word may be used) is composed of yarious thin lamine, 
