VI 



The third species was a Chilian form of undetermined genus, remarkable 

 for the possession of symmetrical mouth-organs. Maxillary palpi 11-jointed. 

 Labial palpi 14-joiuted. 



Mr. M'Lachluii remarked that these drawings were some of the most 

 beautiful and detailed that had ever been e.xecuted for any family of insects. 

 The observation as to the connate nature of the wings in the nymphs of 

 Bcetisca was of great value, as explaining the true nature of the carapace- 

 like thorax of that insect. 



The Secretary exhibited, on behalf of Mr. George Francis, of Adelaide, 

 the microscopical specimens referred to at the last meeting, which had 

 been kindly mounted for exhibition by Mr. William Cole. The series 

 comprised a number of eggs of a Chrysopa suspended in the usual manner 

 by long silken threads from the edge of a Eucalijpti(s-\e?if, and the beautiful 

 shell-like scales formed by a Coccus, together with the insects found beneath 

 the scales. 



Mr. Howard Vaughan exhibited a series of Cidaria russata from York- 

 shire and the Isle of Arran, showing the local variation of this species. 



Papers read, dc. 



The Rev. H. S. Gorham read a paper on the LampyridcB, in con- 

 tinuation of those communicated at the meetings of December, 1879, and 

 February, 1880, the present instalment concluding the revision of the 

 genus Photinus. 



Mr. Gorham also read a paper summing up the results of his observations 

 on the Lampyrlda, with respect to their phosphorescence, which he believed 

 to serve the part of a beacon for attracting the sexes to one another. In 

 support of this conclusion he stated that he had found that the eyes of 

 these species were developed in magnitude according to the amount of 

 luminosity displayed. With regard to the typical species of the family, he 

 had observed that in the most highly organized genera, such as Lamprocera 

 and Cladodes, the light-emitting faculty did not appear to be developed in 

 proportion with the rest of the organs, and that the eyes were also reduced 

 " in a direct ratio with the light," being small and uniform in both sexes, 

 whilst the antennae were " developed in inverse ratio as the phosphorescence 

 is diminished." In illustration of this supposed correlation between the 

 development of the antennae and the intensity of the light, Mr. Gorham 

 exhibited a selection of species arranged in three groups, viz. : — 



(1). Species with plumose antennae, small eyes, and light-emitting sur- 

 face confined to small spots only. {Lamprocera, Cladodes, Vesta, Plianolis, 

 and Megalopihahnus.) 



(2). Species with simple antennae, eyes large, sometimes excessive, 

 both sexes winged ; phosphorescence considerable, sometimes greater in the 

 female. [Cratomorphus, Lucernula, Aspidosoma, Luciola, and Photuris.) 



