NOTES ON THE DRAGONFLY SEASON OF 1912. 79 



On June 22nd, near Huntingdon, a few males of Libellula 

 fulva were taken, and in one of them the left fore wing 

 was in a singularly aberrant condition, as will be seen from 

 the accompanying Plate. Not only is it shorter^ and broader 

 than the corresponding wing on the right side, but the 

 venation is altogether abnormal. Indeed, the homology of 

 some of the veins can hardly be made out at all ; but, 

 apart from this, the wing presents several remarkable charac- 

 ters for which parallels can be found in other groups of 

 Odonata. Thus, the pterostigma is very long, and fills as many 

 as three cells: a "false" pterostigma of this kind is present 

 normally in some Zygoptera. The subcosta is prolonged con- 

 siderably beyond the nodus, as in certain recent .ZEschninae and 

 in the extinct iEschnidiidge. The triangle is of the " Pentathemis" 

 form, and the anal vein, instead of appearing to attach itself in 

 the usual manner to the upper portion of the triangle, takes a 

 downward course towards the hind margin of the wing, as in the 

 iEschnidse. In connection with abnormalities of this kind, 

 Prof. Philip P. Calvert has kindly drawn our attention to Dr. 

 Viktor Janda's valuable paper on regenerated appendages in the 

 Odonata (' Sitzungsber. K. Bohmische Gesell.,' 1909). Several 

 wings of Mschna and Libellula in various stages of re-growth are 

 figured therein, but none of them are quite so remarkable in 

 their venational peculiarities as the wing of L. fulva now under 

 consideration. A living female of Libellula depressa from Hore- 

 ham Road, near Heathfield, Sussex (May 12th), was given to us 

 by Mr. Riley, and Dr. Laidlaw records (in litt.) the taking of a 

 male at Uffculme on May 31st. Mr. R. South gave us two 

 females of Sympetrum striolatunn, taken by himself at Llan- 

 drindod Wells, Radnorshire. He came across them, with others, 

 one afternoon in mid-August, during a brief interval of sun- 

 shine. Owing, no doubt, to the general prevalence of sunless 

 weather, this was the only occasion upon which dragonflies of 

 any kind were observed by Mr. South during some weeks' resi- 

 dence at the Wells. Males and females of Sympetrum san- 

 guineum, in teneral condition, were met with at Ramsey, Hunts, 

 on June 27th. Mr. A. Luvoni showed us an immature male 

 which he had taken at Westcliff, Essex, on July 14th. 



Several of the commoner species were met with again in 

 localities recorded for them in previous years, and for that 

 reason they have not been noticed on the present occasion. It 

 may be added that the Huntingdonshire dragonflies mentioned 

 herein were obtained by Mr. J. Peck and ourselves. 



Explanation of Plate VII.— Upper figure. Libellula fulva, Mull., 

 male, with teratological left fore wing, taken near Huntingdon, June 22nd, 

 1912. Slightly reduced. — Lower figure. The teratological wing, enlarged 

 two and a half times, showing aberrant venation. 



58, Ranela?h Road, Ealing W. : Feb. 12th, 1913. 



