362 PROF. WESTWOOD ON THE GENUS PERGA. [May 4, 



be found adJed to the technical specific descriptions of these two 

 insects. 



Many of the species are remarkable for metallic colours, which are 

 of rare occurrence in the majority of the species of the family to 

 which they belong. 



1. Perga dorsalis. 



Perga dorsalis. Leach, Zool. Mi>c. iii. p. 117, 6 • 

 $ . Perga scutellata, Westw. in Griffith's Anim. Kingd. Ins. 

 pi. 76. fig, 2, and pi. 106. fig. 3, vol. ii. pp. 402, 792. 



"P. cceruleo-chalijbeata ; clypso, lahro, aiileniiis, pleuris macula 



trianguluri, thoracis anguUs unticis, scutello pedibusqae subfer- 



riigineo-luteisy abdomine supra macula magna quadrata sericea 



jiavida externe serrata ; alis julvescentibus, pterygosteorum 



margine stigmateque ferrugiiieis ; mandibutcB luleo-ferruginecB, 



latere interna 7iigricantes. Variat femoribus poslicis apice 



nigris ; abdomen postice subangiistatum. Fcemiaa laiet. Long. 



corp. lOi, exp. alar. 21 j //«." (Leach.) 



Species permagna, maris abdomine macula magna quadrata sericea 



(segmeiita media dorsalia occiipante), alisque ant ids stigmate 



juagno, margine antico pone stigma oblique subtruncalo ; scutello 



in mare piano, in fwrnina macula transversa breviori albida 



notato ; abdcmincque supra viridi-ceneo subnitido. 



Hub. in Australasia (.Moreton Bay &c.). In Mus. Hopeiano 



plurima individua utriusque sexuv. 



The details of the structure of the female published from my 

 drawings in Griffith's 'Animal Kingdom,' pi. 106, were copied by 

 Guerin-AIeneville in his ' Iconngraphie du Regne Animal, lusectes,' 

 pi. 64. fig. 2. Another figure of the female was published by 

 BruUe (' Hist. Nat. Ins. Hym.' iv. pi. 48. fig. 1, p. 6/4) under the 

 name of Perga scutellata. Leach. 



An account of the habits of this species, under the name of Perga 

 eucalypti, was published by Messrs. Bennett and Scott in Proc. 

 Zool. Soc. 1859, p. 209, (Annulosa) pi. 62, with figures of the larvie 

 and of the female insect. 



The larvse were found living gregariouslv on the leaves of Euca- 

 lyptus citriodora and other species, as well as upon Callistemon, 

 which they ra])idly destroy. The lar\a3 were huddled together 

 both on the upper and under sides of the leaves, arranged, for the 

 most part, in regular rows. When disturbed they bend their 

 bodies in the form of an arch, and emit a greenish fluid from the 

 mouth ; they also emitted so powerful an odour of the leaves on 

 which they had been feeding as to scent the room in which they 

 were placed. When full-grown they are from 2-2^ inches long, of 

 a uniform velvety black, with numerous short, stiff white hairs, 

 and with only six large squamous reddish feet, apparently being des- 

 titute of the fleshy prolegs so common in the larvae of Tenthredinida). 

 When feeding, they keep the abdominal portion of their bodies in 

 motion, rapping their extremities against the leaves. They bury 

 themselves underground in October, forming brownish cocoons of 



