Miscellaneous. Ill 



On a Chilian Example of Pterodela pedicularia, L., with doubly 

 abnormal Neuration. By Alfred Giard, Professor at the 

 Sorbonne. 



In the numerous consignments which our colleague Mr. F. 

 Lataste has kindly sent me for the study of Margarodes vitium I 

 have found at different times the larvae, nymphs, and perfect insects 

 of a Psocid which is common in Chili on old vine-stocks, especially 

 at Caillihue and Santa Rita. This is Ciecilius pedicidarius, L., 

 which Jvolbe has made the type of the subgenus Pterodela. 



The species is widely distributed in Europe on old wood of various 

 kinds and even in dwellings, where the imago is seen from the 

 end of August to about the 15th of October. In Chili the perfect 

 insect commences to appear about the month of December, and at 

 this period there still exist many untransformed larvae. 



These Chilian examples do not differ from those of the old world. 

 Their size is perhaps a little less and the pterostigma a little 

 more cloudy. It seems to me evident that this Psocid has been 

 introduced into Chili with some vegetable debris, perhaps with the 

 vines themselves. It is not mentioned in tho list of Neuroptera 

 in C. Gay's ' Histoire Naturelle du Chili.' 



By a singular coincidence the first adult example which I received 

 from Caillihue, a male, presented an abnormal neuration, and ab- 

 normal in a different manner in each of the two anterior wings, 

 so that I was some time in recognizing our common Ciecilius pedi- 

 cularius, L., and my doubts only vanished later when M. Lataste 

 sent mo fresh and perfectly normal specimens. 



The study of teratological cases in the neuration of insects 

 presents considerable interest from the point of view of biological 

 philosophy. It is important not to lose the documents which nature 

 has furnished us with in so unusual a manner, and for this reason I 

 have thought it advisable to describe and carefully reproduce the 

 wings of the abnormal Ciecilius of Chili. 



If we compare the left wing of the abnormal specimen (fig. 1) 

 with the left wing of a normal individual (fig. 3), we see that the 

 second posterior marginal cellule (B) is wanting, the median nervure 

 sending only one branch to the margin of the wing instead of two. 

 This is a simplification of the neuration which is only met with in 

 the normal state in the inferior wing in the Psocids (cf. fig. 4, the 

 inferior wing of Ccecilius pedicidarius). 



De Selys Longchamps has described an analogous monstrosity in a 

 Psocus bipunctatus, Latr., from the Rambur collection. In the 

 genus Psocus there are normally four posterior marginal cellules. In 



