CLASSIFICATION OF PALEOZOIC INSECTS. ;;•_>;, 



The following are some of the forms falling here, arranged, as far as may be, in their 

 natural sequence. 



Acridites priscus. 



Acridites priscus Axdkee, Neues Jahrb. Miner.. 1864, 163-164, pi. 4, fig. 1. 



This species is remarkable for the great length of the mediastinal vein and its uniform 

 distance from the margin, which suggest that it may be a hind wing. Andree referred it 

 to Orthoptera. It comes from the Bohemian coal measures at Stradonitz. 



A fragment of a wing, figured here on pi. 29, fig. 9, seems to come in this vicinity. It is 

 remarkable for the excessive length of the mediastinal vein, the longitudinal obliquity of 

 the branches of the same, and the confinement of the branches of the scapular vein to one 

 or two brief nervules at the very tip of the wing. The externomedian branches seem to be 

 almost similarly confined, while the internomedian branches are crowded, nearly straight, 

 and simple or apically forked. It also has the appearance of a hind wing. It comes from 

 the carboniferous beds of Mazon Creek, 111., and was received from Mr. R. D. Lacoe, in 

 whose collection it bears the number 2055. 



Eucaenus (t'n, koivo's) gen. nov. 



Stout bodied, the thoracic segments twice as broad as long, the meso- and metathorax 

 very large ; the abdomen ovate, the final segments with a median keel ; front wings very 

 regular, oblong obovate, the costal border uniformly arcuate, the mediastinal vein straight, 

 terminating before the apical third of the wing, with numerous straight, simple and regular 

 brandies; scapular vein terminating midway between the end of the mediastinal vein and 

 the tip of the wing, with similar branches- externomedian vein very important with rather 

 distant branches. 



Eucaenus ovalis sp. nov. PI. 29, fig. 4. 



The fore-wings are very regularly rounded, a little more than three times as long as broad, 

 the tip situated rather below the middle, only a little above the termination of the middle 

 externomedian branch ; externomedian branches about five in number, taking a course 

 about parallel to the apical third of the costal margin, very distant compared to the 

 mediastinal branches, always forked, sometimes doubly; anal veins more oblique, numerous 

 and parallel. The prothorax has a slight median ridge, and the flat fore femora are 

 minutely, distantly and rather coarsely. granulate. Length of body (excepting the missing 

 head) 22 mm., breadth of abdomen 7 mm., length of front wings 22 mm., their probable 

 breadth 7 mm. 



A single specimen is known from Mazon Creek and bears, in the collection of Mr. R. D. 

 Lacoe. the number 2049. 



G-erapompuS (ynpa- . irop/iro's ) gen. nov. 



Body slender, elongated, the meso- and metathorax tolerably stout, but the prothorax at 



