Sept., 1909.] Proceeding of the Society. 189 



his operations with the larvie of hia habella, which were influenced by change of 

 moisture. Many in wet environment were uniformly black, whereas in dry situa- 

 tions the many black bands failed to develop and the larvae remained unicolorous. 



Mr. G. W, J. Angell exhibited a series of the water beetle, Hydrobius tessellattis, 

 taken in clear water at Westwood, N. J. These were all normal and uniform, while 

 a single specimen taken in very dirty water was aberrant. 



Society adjourned. 



Meeting of April 6, 1909. 



Held at the American Museum of Natural History. President C. W. Leng in 

 the chair with seventeen members and one visitor present. 



The librarian reported the receipt of the following publications since March 2 : 



Cold Spring Harbor Monographs, VH. 



Entomologiske Meddeleser, Vol. HI, No. 4. 



Canadian Entomologist, Vol. XLI, No. 3. 



Zeitschr. f. wissenschft. Insektenbiologie, V, No. 2. 



Wiener Entomol. Zeitung, XXVIII, No. 2. 



Zoological Record, Injects, XLIV. 



Charles Janet. Notes extraites des Comptes Rendus des Seances de 1' Academic 

 des Sciences, Nos. 16-20. 



Charles Janet. Anatomic du corselet et Histolyse des Muscles Vibrateurs, apres 

 le vol nuptial, chez la reine de la fourmi. 



The Insect World, XIII, Nos. i, ^. 



Deutsche Entomolog. Zeitschrift, 1909, No. 2. 



The House-fly. Ent. Circ. 25, No. C, State Dept. Agric. 



Mr. Leng spoke of the recent death of Mr. Wm. Edwards and read a brief 

 notice which had appeared in the New York Sun. 



Dr. R. C. Osburn spoke on the " Species of the Sy7-f>kus arcitaius Grow.Y>-'^ He 

 said that this group of the Syrphidte was a very difficult one to study, but after examin- 

 ing material from several collections, including that of the American and National 

 Museums and representing in distribution some twenty states and several provinces of 

 Canada, he had found certain well-marked characters by which the species of arcua- 

 tus and the form lapponicus might be separated. These were differences in the vena- 

 tion, characteristic maculation on the frons and differences in coloration of the 

 thoracic pile. The areas of enlarged eye facets in the males were also noted. The 

 differences in coloration were found to be somewhat variable and not so constant a 

 character as those noted above. Specimens illustrating the difTerent forms were shown 

 and the question of the names discussed. 



Dr. Osburn also discussed the intergradations of Scava with Syrphus and said 

 that the species /j/vrj/r/ L. had been placed by Osten-Sacken in the genus Cataboma 

 in his paper on " Western Diptera," but had previously been assigned to the genus 

 Scccva. This species had been separated from Syrphus on the characters of the frons, 

 the pilosity of the eyes and the venation. Dr. Osburn pointed out that various species 

 in the genus Syrphus showed differences as marked as this species in these respects, 

 and he did not believe that such characters could be regarded as being of specific 

 rank, although they might be useful for grouping certain species within the genus 

 Syrphus. 



