TOXOPTERA. 135 



Although, the galls in EDglancl take several forms, I 

 am not disposed to multiply species on this account. 



Some structures have two peduncles, some have two 

 orifices, some spring from the midrib, whilst others 

 rise from the green fleshy portion of the leaf. All 

 these show a purple colouring at their apices. 



The genus Toxoptera was formed by Koch to receive 

 some insects which are somewhat anomalous, inasmuch 

 as they combine the characters of Mijzus and, as far as 

 the wing-veining goes, of Pem])higiis. 



Two species are known of this genus, viz. Toxoi^tera 

 aurantice, Koch, and T.graminum, Eondani. The former 

 is common on the Orange, the Citron, and the Camelia 

 in Germany, South France, and Italy ; but, as these 

 trees are exotics here, this Aphis cannot be regarded 

 as indigenous to Great Britain. Toxoptera graminum, 

 during the summer, is an inhabitant of various Grasses, 

 affecting the lower leaves, and numerously so. 

 Triticum, Hordeum, Avena, Sorghum, and Zea are 

 habitats of this species. 



The characters of Toxoptera are : Antenna seven- 

 jointed, and placed on small remote frontal tubercles. 

 Cornicles and tail moderately long. Wings with the 

 cubital vein but once-forked. The rest of the characters 

 as in Myzus. 



Rondani says that in the year 1852 the streets of 

 Bologna were swarming with innumerable troops 

 (" turmis innumeris ") of T. graminum to the annoy- 

 ance of the inhabitants. " Urbis nostrse vias cadavera 

 hujus formjB primo mane velabant."* I suppose a 

 little exaggeration may be allowed to an enthusiast. 



Sir Joseph Hooker kindly made several searches for 

 this Aphis in the orangery of the Royal Botanical 

 Gardens at Kew, and Sir Charles Isham also made 

 examinations of the plants in his fine camelia house at 

 Lamport Hall. 



In both cases the search was ineffectual. 



* Rondani ' Ann. delle Scien. Nat. de Bologna.' 



