SOCIETIES. 269 



under side of a very dark colour, identical with typical specimens of 

 the second brood. He thought the peculiarity of colouring in this 

 specimen had been caused by a retarded emergence from the pupa, due 

 to low temperature and absence of sunshine. Mr. F. W. Frohawk 

 exhibited a series of striking varieties of Saiyrus hyperantJms, bred 

 from ova laid by a female taken in the New Forest in July last. Mr. 

 F. D. Godman exhibited a specimen of Amphonyx medon, Cr., received 

 from Jalapa, Mexico, having a pouch-like excrescence at the apex of 

 its body. Mr. McLachlan, Mr. H. J. Elwes and Mr. Poulton 

 commented on it. Mr. C. J. Gahan communicated a paper entitled 

 "Additions to the Longicornia of Mexico and Central America, with 

 notes on some previously recorded species." Mr. W. L. Distant com- 

 municated a paper entitled " Contributions to a knowledge of the 

 Homopterous family Fulgoridse." Mr. Oswald Latter read a paper 

 (which was illustrated by the Society's new oxy-hydrogen lantern) 

 entitled " The Secretion of Potassium-Hydroxide by Dicranura vinula, 

 and the emergence of the imago from the cocoon." The author stated 

 that the imago produced, probably from the mouth, a solution of 

 caustic potash for the purpose of softening the cocoon. The solution 

 was obtained for analysis by causing the moths to perforate artificial 

 cocoons made of filter-paper. Professor Meldola said that the larva of 

 D. vinida secretes strong formic acid, and Mr. Latter had now shown 

 that the imago secretes potassium-hydroxide, a strong alkali. He said 

 he had long been familiar with the fact that secretion from the imago 

 of D. vinula was alkaline to test-paper, but he had never investigated 

 its composition : and he also stated that the fact that any animal 

 secreted a strong caustic alkali was a new one. Mr. Merrifield, Mr. 

 Hanbury, Mr. Gahan, Mr. Poulton, and Prof. Meldola continued the 

 discussion. Mr. H. J. Elwes and Mr. J. Edwards read a paper, also 

 illustrated by the oxy-hydrogen lantern, entitled " A revision of the 

 genus ypthima, principally founded on the form of the genitalia in the 

 male sex." Mr. McLachlan said he attached great importance to the 

 genitalia as structural characters in determining species, and he believed 

 that he could name almost any species of European Trichoptera simply 

 from an examination of the detached abdomens of the males. Mr. 

 Osbert Salvin said he had examined the genitalia of a large number of 

 Hesperidae, with the view of considering their value in distinguishing 

 species, but at present he had not matured his observations. Mr. 

 Jacoby, Mr. Bethune-Baker, Colonel Swinhoe, Mr. Lewis, Dr. Sharp, 

 Mr. Hampson, and Mr. Champion continued the discussion. Mr. S. 

 H. Scudder communicated a paper entitled "New light on ihe 

 formation of the abdominal pouch in Farnassius." Mr. Elwes said he 

 had based his classification of the species of this genus largely on the 

 structure of this abdominal pouch in the female. Mr. Jenner Weir 

 remarked that a similar abdominal pouch was to be found in the genus 

 Acrcea ; and Mr. Hampson referred to a male and female of Parnassius 

 in Mr. Leech's collection, in which the pouch had come away from the 

 female and was adhering to the male organs. — H. Goss and VV. W. 

 Fowler, Hon. Secretaries. 



City or London Entomological and Natural History Society. — 

 Thursday., zoih October^ 1892. — Exhibits: — Mr. Hollis, Colias hyale diWdi 

 C. edusa var. helice, also a series of Feronea varie^ana and living larvae 



