12 MIOCENE FAUNA. 



If the CEningian spiders are compared with those which have 

 been discovered in amber, no exactly accordant species are found ; 

 but there are some nearly allied species*. Most of the amber- 

 spiders may be referred to existing genera ; but some of them are 

 of extinct types, one of which (Archaea) forms a distinct and very 

 remarkable family. Amber encloses a great number of species 

 of spiders, the resin flowing from the amber-bearing trees having 

 enveloped the animals dwelling under the bark, or sitting on its 

 surface, and embalmed them for ever. 



Of the great section of the Mites (Acarina) a single species has 

 been found at (Eningen. It is a little oval animal, 1 millimetre 

 (039 inch) in length and | millimetre in breadth, with eight 

 delicate legs of nearly equal length. 



c. Insects. 



Notwithstanding their small size and their delicate fragile 

 structure, so many species of insects have been preserved that 

 the class of insects must have included the great mass of species 

 of animals. Only 33 species of insects have remained in the 

 Swiss Miocene ; but from (Eningen we have 844, only one of 

 which occurs in the Swiss Miocene, so that at present we know 

 876 species belonging to the Swiss environs. Of these, 543 species 

 are Beetles, 20 Orthoptera, 29 Neuroptera, 81 Hymenoptera, 

 3 Lepidoptera, 64 two-winged flies, and 136 Hemiptera or 

 Bhynchota. The beetles are consequently the most numerous ; 

 and they are followed in order by the Rhynchota, the flies, and 

 the Neuroptera. The Lepidoptera "(butterflies and moths) are 

 most feebly represented both in species and individuals ; for Prof. 

 Heer has hitherto seen only 5 specimens of Lepidoptera (perfect 

 insects and larvse) from (Eningen, whilst he has examined 2456 

 specimens of beetles, 882 Neuroptera, 699 Hymenoptera, 310 flies, 

 598 Hhynchota, and 131 Orthoptera. Of the Neuroptera only 

 about 80 specimens are in the adult state, all the rest being larvse 

 of dragonflies, which lie in a particular bed at (Eningen, and were 

 probably killed by some sudden catastrophe, so that a great part 

 of the insects contained in the pit have been preserved. Hence 



* Clubiona JEseri is very like C. lanata ; and Macaria tenella resembles 

 Macaria procera, B. & K. 



