3 Dr. LieuTENSTEiN's Dijfertation on two Natural Genera 



added to our knowledge of infeas within thefe twenty year? by him- 

 felfand other aaive naturahfts ! And- yet we are ftill very far from 

 having a proper natural arrangement and defcription of all the orders 

 and genera. I ftvall fay nothing of the fpecies ; for here, efpecially 

 through the impcrfeaion and frequent incorreanefs of the fynonyms, 

 fo mudi confufion prevails, that it is often difficult to afccrtain to 

 what fpecies of Linne or Fabricius a perfeaiy common indigenous 

 iufea belongs. If a genus be truly natural, or, as logicians call it, 

 ^ genus proximiim, a fingle charaaeriftic is almofl always fufficient to 

 determine with certainty to what fpecies an individual of this genus 

 is to be referred. The prefent attempt may ferve as a fpecimen of 

 the manner in which I conceive that ftill greater genera ought to be 

 treated according to the natural diftinaions ; fixing the natural ge- 

 nera where the fyftem has not already done it, and placing the 

 fpecies in order under appropriate fubdivifions taken from efTential 

 differences ; defcribing them with accuracy, and particularly adding 

 the fynonyms as completely and correaiy as poffible. 



The idea of feparating from the proper Mantes thofc fpecies feeding 

 on plants, that have no falciform fore-feet, but have all their legs 

 formed for running, and making a new genus of them, is by no 

 means of my invention. Cafpar StoU has already propofed it, but 

 has not at all carried it fyftematically into efFea. The fplendid 

 work which this zealous entomologift had begun to publilh at Am- 

 fterdam in 1787 with a Dutch, and French text, under the title of 

 Naluurlyke, en naart leeven nauivkeurig geU'eurde AJbeddingen, en Be- 

 fchryvingen der Spooken, Wandeltide Bladen, Zabelfpr'inghaneu, Krekeh, 

 ^rekjpringhaantn en Kakkerlakken, in quarto, fold by J. C. Sepp,. was in- 

 terrupted by death, which cut off this gentleman (who, with many 

 peculiarities, had yet undeniably great merit) in the middle of his 

 career. Had he lived longer, this work on the Ulonata of Fabricius 



would. 



