3 50 BHITISH APHIDES. 



furnished the geologist with the finest specimens of 

 extinct Aphides and allied insects. 



There are, however, other sources which yield evi- 

 dences of the existence of Aphides in ages long past. 

 The fossil resin known as amber has been studied by 

 Hope, Menge, Germar, Berendt, Goeppert, and others ; 

 and within the masses well-marked genera of insects, 

 closely related to recent ones, are clearly indicated. 



In the Permian and Trias formations comparatively 

 few fossil insects have been hitherto traced. Professor 

 Heer noticed but one Orthopterous, three Nenro- 

 pterons, and three Coleopterous forms. 



On the other hand, the insects of the Lias are very 

 abundant. Previous to the examination of the Lias 

 beds of Schambelen, in the Canton of the Argau in 

 Switzerland, only fifty-six species had been described ; 

 but Heer obtained later about 2000 specimens, which he 

 referred to 143 species. Of these the Coleoptera were by 

 far the most frequent; for they numbered 116 species. 

 After them came the Hemiptera, which comprised 

 twelve species of numerous individuals. A well- 

 preserved portion of a wing, showing characters very 

 similar to those of an ant, proves the occurrence of 

 Hymenoptera in these early times. 



Most of these insects are figured in ' Die Urwelt der 

 Schweiz ; ' but I will only specially allude to the Hemi- 

 ptera, as being the order more immediately connected 

 with my present subject. 



The ancient Hemiptera in great part appear to have 

 had sanguinary habits, for such we may infer from 

 the construction of their suctorial rostra, formed 

 for drawing blood and extracting the juices of insects. 

 Eight species are mentioned as obtained from tho 

 Liassic marls situated about half way between Zurich 

 and Basle. Two of them are figured. One, viz. 

 Protocoris insights, is about half an inch long, and 

 very decidedly shows its Hemipterous characters. We 

 may remark that the English fossil Hemiptera were 

 certainly not larger than our existing species. 



