rg6 PHYS1S (V, 19:12) 



Morphological characters : Dorsum provided with small pilife- 

 rous tubercles as in apterous form. antennae with faint imbrica- 

 lion mi l\ , becoming inore definite on \. \1 and filáment. III 

 with liairs as in apterous form and withabout :k> rather small sen- 

 soria situated in more or less a straight royv over ils entire length. 

 Frontal tubercles slightlS gibbous on inner apical angle. Cornicles 

 and canda as in apterous virgogene. I3eak attains second coxae. 



Relative measurements : 



Length 2 .3o 



YY id tli 1 . 00 



f. t. I II III IV V VI f. 



Antennae 0.06 o. 11 0.08 0.71 o. 55 0./I7 o.i5 0.82 



Cauda. o. 2 5 



Cornicles o. 5" 



I st 2"" 3" 1 



/Femora... o. 84 °-79 1.02 



Legs J Tibiae ... i.5i i.48 1 . 75 



'Tarsi..... o.i4 o.i5 o.i5 



Rostrum. 0.60 



Hab. Common in San Isidro, Lomas de Zamora, Buenos Aires; on 

 Urtica, Malva and Geraniam. 



Genus AULACORTHUM Mordwilro 



The two species dealt with may be separaled by the following key : 

 1 . Segment IV of antennae of al ale virgogene with sensoria. 



Segment IV of antennae of álate virgogene without sensoria 



1. pseudorosaefolium Bl>chd. 



without sensoria 



A. eumorphum Bl>chd. 



Aulacorthum eumorphum n. sp. (fig. 6) 

 Apterous virgogene. 



Color : Green to palé green. Eyes reddish. Antennae yellowish 

 with the three apical segments darkened. Legs palé, greenish to 

 yellowish with the tarsi, and lips of femora and tibiae blackish. 

 Cauda greenish. Cornicles greenish with the ápices slightly darke- 

 ned. Rostrum concolorous with the body, ils extremity dusky. 



