ne Ohio ^hCaturalisty 



PUBLISHED BY 



The Biological Club of the Ohio State Uni<versity, 

 Volume II, APRIL, 1902. No. 6. 



TABLE OF CONTENTS 



OsBOEN AND BALL— North American Species of Athysanus 231 



COLTON — A Possible Cause of Osars 257 



Kelleemax and Jennings— Smut Infection Experiments 25S 



DUFOUR— Trailing and Creeping Plants of Ohio 201 



Kelleeman— Corrected Description of Phyllosticta alcides 262 



Tyler— Meeting of the Biological Club 262 



A REVIEW OF THE NORTH AMERICAN SPECIES 

 OF ATHYSANUS (JASSIDAE.) 



Herbert Osborn and E. D. Ball. 



The genus Athysanus Burm. is world wide in distribution and 

 in many of the fauual areas is represented by a large number of 

 species. Being one of the older Jassid genera it has like Delto- 

 cephalus been made the abiding place of a very heterogeneous mass 

 of material. One \)y one the more strikingly distinct forms have 

 been taken out and placed in genera of their own, leaving as a 

 residue species whose strongest bond of union is probably their 

 lack of distinctive generic characters upon which to separate them. 

 As has already been suggested this confusion has been greatly 

 augmented by the use of " the second cross nervure" as a final 

 test between this group and the Deltocephalinae. With every 

 addition to our knowledge this character loses in value as a correct 

 test of the separation of these groups and is now only regarded 

 as of limited application between different genera in each series. 



Under such conditions it was found to be almost impossible to 

 give any characters to the group that would apply to all the in- 

 cluded species. An examination of a series from Europe showed 

 that their fauna was even more complex than ours but that it 

 would nearly all fall into the same groups and that most of the 

 remaining species belonged to genera already set off in America. 



In the present paper an attempt has been made to arrange the 

 North American species still remaining in this genus in a series of 

 groups sufficiently homogeneous in character to be defined and 

 thus give a basis upon which to work in future studies on related 

 genera. In the following out of this plan a few species were elim- 

 inated as more closely related to other genera and then it was 

 found that the remainder could easily be arranged in four series 



