Vol. XXIX] I'.XTOMOI. ()C,I( AT. XF.WS. 365 



Cornicles barely distinguishable, being only small pores. Body oval 



and distended, particularly in the apterae 2 



2. Antennae five-segmented. Cauda of alates long and ensiform, and 



of apterae short and conical, but well developed 



Siphonatrophia nov. gen. Type: Ccrosipha cuprcssi Swain. 

 Antennae six-segmented. Cauda short and tapering and not developed 



in the apterae 



C r\'ploxi[>lntin Buckton. Type: C. artcmisiac Buckton. 



III. THE GENUS MONELLIA OESTLUND. 

 In 1887 Oestlund 8 described the genus Monellia with Aphis 

 caryclla Fitch as the type. He separated this genus from 

 Calliptcnts Koch by the position of the wings when at rest. In 

 the latter they are held roof-like as is typical in the Aphididae, 

 while in the former they are horizontal, that is, laid flat on the 

 abdomen. Following is Oestlund's description of the genus : 



Antennae longer than the body, on no frontal tubercles. Eyes 

 pale red ; ocelli present. Beak very short. Thorax low and flat ; pro- 

 thorax nearly as large as thorax proper. Wings held horizontal in 

 repose; venation as in Calliptcnis. Honey-tubes not obvious. Style 

 short, enlarged at apex. 



As just stated, Aphis caryclla Fitch was designated as the 

 type. In this species the wings are said to lie horizontal when 

 the insect is at rest. Many times in California there has been 

 taken on walnut a species which has been considered as caryella 

 Fitch. Careful comparisons with mounted specimens from 

 Indiana show no structural differences, so that there can be no 

 doubt that they are identical. However, the species in Cali- 

 fornia does not have the habit of holding the wings horizontal 

 when at rest. It would seem, therefore, that this habit is 

 variable. 



Many of the American aphidologists have considered Callip- 

 terns caryac Monell as belonging to this genus. Here is another 

 species that does not have this habit, at least in California. 

 Specimens from California agree perfectly with specimens in 

 the writer's collection from Pennsylvania. The writer has been 



8 Oestlund, O. W. Synopsis of the Aphididae of Minnesota. Bull. 

 Minn. Geol. and Nat. Hist. Survey, 4:44. 1887. 



