Handlirsch — New Paleosoio Insects. 297 



Art. XXVIII. — New Paleozoic Insects from the Vicinity of 

 Mason Creel:, Illinois ; by Anton Handlirsch, Imperial 

 Natural History Museum, Vienna. 



The Carboniferous (Pennsylvania) ironstone nodules found 

 in and around the region of Mazon Creek, Illinois, form an 

 inexhaustible source for our knowledge of the Paleozoic 

 insect world. Each new series of these precious pebbles 

 examined furnishes new and interesting forms of insects, but 

 rarely has one and the same species been represented by more 

 than a single specimen. This fact seems to indicate that the 

 species hitherto discovered are but a small fraction of the 

 whole insect fauna of these far remote times. The more grate- 

 fully, then, must we acknowledge the courtesy of Professor 

 Charles Schuchert, who has again supplied for study and 

 description a rich series of fossils, preserved in the geological 

 collections of Yale University. Some years ago he sent me 79 

 specimens, all from the vicinity of Mazon Creek, Grundy 

 County, Illinois, 11 of which have previously been described. 

 Besides 1, which is a Scorpion, and 17, which I am absolutely 

 unable to determine, I have been able to classify them all. 

 Only 4 of the fossils not hitherto brought to notice belong to 

 known species (Euccenus ovalis Scudder, E. mazonus Melan- 

 der and two Blattoidea) ; all the others are new to science. It 

 was necessary to establish for these 40 new species, 23 new 

 genera, 9 new families and even a new order. Nevertheless, 

 the whole can be introduced into the scheme established in my 

 "Fossil Insects." All the new forms are evidently hetero- 

 metabolic. With the exception of some Blattoidea there is 

 not one type of a modern order to be found in the collection. 

 The Palseodictyoptera are well represented by 6 species; 

 many of the other forms belong to the extinct intermediate 

 orders which lead from the Palaeodictyoptera to the modern 

 types (1 Protodonata, 2 Megasecoptera, 19 Protorthoptera, 8 

 Protoblattoidea, 1 Sypharopteroid). Only 3 of the new species 

 belong to the Blattoidea. 



The fauna of Mazon Creek seems to have been of a similar 

 character to that of Commentry, Belgium, and Saarbriicken 

 of Europe. It was a fauna of giants in comparison with that 

 of our day. 



Order PALAEODICTYOPTERA (Goldenberg). 



Family DICTYONEURIDiE Handlirsch. 



This very archaic family, represented by 30 species in the 

 middle productive Carboniferous deposits of Europe (Com- 

 mentry, Saarbriicken, Hennegau, etc.), seems to be much les6 



Am. Jour. Sci. — Fourth Series, Vol. XXXI. No. 184. — April, 1911. 

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