Feb., 1909.] Definition of Nysson and of N. aurinotus. 445 



but the form of the seventh dorsal segment is sufficient to sepa- 

 rate it, armatus having only two distinct teeth on this segment 

 and texanus having four. 



Say's description of Nysson aurinotus applies equally well to 

 armatus and to texanus, with the exception of size ("three-tenth 

 of an inch") in which it agrees precisely with armatus, and not a 

 word of his description is at variance with either. But as Say 

 did not mention the armature of the abdomen and probably 

 knew only the female it is hardly safe to adopt his name for one 

 of them to the exclusion of the other. As it is possible that speci- 

 mens ma}^ be found showing connection between the two forms 

 of the seventh segment, it is not impossible that Say's name 

 may yet find recognition, but no such connection is now known. 

 The name given by Say, meaning "gold-known," indicates a 

 ver}' essential and "prominent" character of texanus, and the 

 absence of yellow marks on prothorax and scutellum is charac- 

 teristic of American Paranyssons and shows clearly that Say's 

 species has no relationship with sequalis. The female specimens 

 from Illinois described by Mr. Cresson under aurinotus belong to 

 N. a^qualis Patton. The males of sequalis and N. plagiatus do 

 not differ from one another in form of eighth ventral segment and 

 claspers. 



Agenioxenus. To Mr. AV. J. Fox is due the credit of referring 

 rufiventris to synonomy with robinsoni Cress, (cf. Tr. A. E. S., 

 1892, p. 57.) The species is easily distinguished from all others 

 by the male antennae being longer than both head and thorax. 

 Cresson 's figure shows hind cubitus interstitial. 



The specimen in the Riley collection should be re-examined, 

 and Walsh's figure compared. The form of prothorax and of 

 metathorax may have been modified in mounting. In Taschen- 

 berg's C. abnormis, c? from Rio, the venation is as described for 

 Agenioxenus. 



