56 BULLETIN OF THE NATURAL HIsTORY SOCIETY. 



of this locality. In lustre and hue they differ from the plant 

 remains, which are of a pure grey and more lustrous, often 

 brilliantly so, on account of their graphitized surfaces. 



The body of this insect is cracked longitudinally and flattened 

 by pressure. On the right side the margin is perfect throughout, 

 but on the left it is broken away, or crushed in, from the head to 

 the second joint of the abdomen ; on this side also the margin is 

 slightly pushed in at the last two segments. These defective 

 parts are restored in the figure. 



Comparisons with other Species. Such is the peculiar aspect 

 of this fossil that only with hesitation can one refer it to any 

 existing order of insects. There are apterous forms among the 

 Hemiptera which may seem to have points in common ; such are 

 the lice, but in these the sucking tube is soft, whereas in 

 Geracus, judging from its distinct preservation in the stone it 

 consisted of hard chitin, and the head is not distinctly separated 

 from the thorax. 



There is a superficial resemblance in the conical head and 

 long proboscis to the weevils among the Coleoptera, and the 

 small number' of rings in the abdomen is also a feature in which 

 it resembles these compactly liuilt little insects, but the loosely - 

 jointed Ijody is quite at variance with the structure of the 

 weevils ; and there were no wings. 



As regards the size and to some extent the form of the head, 

 Geracus compares with more than one of the Paheozoic insects. 

 Thus Lithomantis carhonaria Wood, fi'om the Carboniferous of 

 Scotland* has a small pointed head with an elongated anterior 

 pi'ocess ; and a similar head, but with a long lance-like sucking 

 tube belongs to Eugereon Boeckingi Dohrn, of the Permian of 

 Germany ;t this tube is about the same proportionate length as 

 that of Geracus. In both these insects, however, the head is 

 distinctly separated from the thorax, and not connected by a 

 broad base as in our species ; they also have transverse!}- oval 

 prothoraces. 



♦Quart. Jour, Geol. Soc. London, Vol. xxsii., pi. 9, 1S7C. 

 t Palseontograph. Bd. xiii., Taf. 41, Cassel 1866. 



