1892.] 



THE BRITISH NATURALIST. 



37 



some very large examples of Paliidina Hstera from Mr. Milne, of 

 Bowden, Cheshire, the largest measuring 43 mm. by 36 mm., these I 

 placed in the aquarium, and they all favoured me with a brood of 

 young in the course of a very few days, but the progeny never reached 

 a large size, though they flourished fairly well, and their decendants 

 are still living in the trough, though greatly diminished in number by 

 the severe winter of 1 890-1, which had but little effect on the LimnacB. 

 Their average size is about 30 mm. by 25mm. — W. A. Gain, Tuxford. 



Errata in January Number. 



Page 15, line 16. — For ''refracted" read "reflected." 

 Page 16, line 5. — For "the most" read "this most." 

 Page 16, line 8. — Read "so that a considerable number." 



DRAGON FLIES. =^ 



BY F. MILTON. 



Dragon flies were formerly included in the order Neuroptera, but 

 they are formed into an order by themselves called Odonata, but 

 what that term means no one seems to know. Dr. Hagen, in the 

 Entomologist's Annual for 1857, divides them into two Tribes, and 

 these again into six Sub-families, the chief distinguishing features 

 being their eyes and wings. The thorax is large and round, and 

 difl'ers from that of other insects in the great development of the side 

 pieces, especially the episterna, and also in the very small prothorax. 



In the first sub-family, Libellulid^, the hind wings are larger 

 than the fore wings, and also dilated at the base; upper part of 

 clypeus, or face, grooved; eyes not prolonged backwards; abdomen 

 rather short. In the second sub-family, Cordaliid^, the eyes are 

 not contiguous, the upper part of clypeus rather round, abdomen club- 

 shaped in the male, wings unequal. In the fourth family, ^schinid^, 

 the eyes are completely contiguous, and the wings unequal ; they have 

 also an opaque triangular spot at the base of the hind wings. 



Now we come to the second tribe and fifth family, Calopterygid.e_. 

 Here we have the wings equal, and eyes not contiguous, head not 

 round like the preceeding, but barrel-shaped and horizontal. The 

 sixth family, Agrionid^e, all very similar to the Calopterygid.e but 

 much smaller. These brief descriptions will enable anyone to 

 distinguish the families. 



* Read at a meeting of the City of London Entomological and Natural History 



Society. , 



