NEUROPTKRA. 229 



1905. Petkrs?:n, Wilh. — I'ber die Bedentung der Generationsorgane 

 fur die Entstehnng der Arten. Com. licii'l. Gth Coiui. int. 

 ZnoL, pp. 213-224^ iWi-ne. 



1905. Petersen, Wilh.- Ziu- ]''rage der Geschlechtswitterung bei 

 Raupen. Knt. Zcit. (Gabeii), vol. xix., pp. 20, 22-23. 



Gil ben. 

 1905, -Jordan, K. — Note on a peculiar secondary sexual character 

 found among Gefniiftridai' at the sensory organ .-iituated at 

 the base of the abdomen. .Vor. Znol., vol. xii., pp. 506-508. 



Trmg. 

 1905. Petersen, Wilh. — Ueber beginnende Art-Divergenz. ArcJi. f. 

 Bass. 11)1(1 Gi'ssells.-BioL, vol. ii., pp. 641-6G2. Berlin. 



(To he concluded.) 



EUROPTERA. 



Pterodela livida, Enderlein, a Psocid new to the British Fauna. 



(./'>• 1-5). 

 By RICHAUD S. BAGNALL, F.L.S., F.ES. 



Whilst I cannot pretend to have made a study of the Psnciilae I 

 have taken sufficient interest in the group to tempt me to gather 

 together a certain amount of literature on the European species. 



One day in July I had the opportunity of spending a couple of 

 hours in Whittle Dene, near Ovmgham-on-Tyne, accompanied by 

 Prof. Hudson Beare. Our visit was planned in the hopes of securing 

 imagines of an unknown thrips, of which I had discovered the very 

 distinctive larvte upon hazel a couple of months previously. There 

 was no sign of this thrips, however, either larval or imaginal, though 

 the readily recognised red and white banded larvae of Ha/dnthriiis 

 obsciirijiennis, Bagnall, turned up, being previously known from the 

 Oxford district, where it is not really uncommon, and widely distri- 

 buted. 



I bottled an interesting Hemipteron and several Psocids, especially 

 minute forms, including a light yellow I'ti'rodela, which I thought 

 might be referable to Pteroilcla liiiila. The specimen was luckily a 

 c? , and examination in a rough glycerine mount proved at once that 

 it was undoubtedly referable to that species, described by Dr. Gunther 

 Enderlein from Gohren, in Riigen Island, Prussia. 



Pterodela liviua, Enderlein. 



Zool. Ja/irb., xviii. Abth. f. Syst., 1903, p. 374, pi. 3, 4, 6 and 9. 



This species, together with /'. (jKerciis, Kolbe, differs from the well- 

 known /'. pcdicidaiid, L., of which specimens are running about on 

 the curtain and window-sill as I write, by the type of gonapophysis in 

 the J , the latter having this organ roundly curved in the form of a 

 crook, and simple at apex instead of bifurcate as in the former. 



/'. lirida is a shade smaller (length of forewiug l-5mm.-l-6mm.) 

 than /'. jifdiritlaria, and_ distinctly smaller than 1'. ijucn-Ks, and differs 

 from both in its light yellow coloration ; the wings are hyaline with 

 light yellow veins, and from P. tjiiercits, apart from size, colour and 

 general appearance, /'. livida is at once se]J)arable by the form of the 



