392 ENTOMOLOGICAL SOCIETY 



f 



As it seemed from the description that the species of this genus 

 were distinguished largely by color, discussion followed in regard 

 to the taxonomic value of color. Dr. Gill spoke of the great 

 variation in the value of color in different groups of animals. In 

 birds, for example, the color seems to be very constant, while in 

 certain mammals it is very variable in the same species, although 

 the modern school of mammalogists are coming to use color varia 

 tions as specific. With shells there is great color variation. Dr. 

 Dyar said that in some groups of moths the color was variable 

 within specific limits. Mr. Schwarz said that in beetles the value 

 of color differed in different groups. In the Cicindelidae there is 

 . considerable variation, but it follows a definite, law as pointed out 

 by Dr. Horn. In the CoccinellidaB and Chrysomelida3, many 

 species are very variable, but there the law of variation is obscure, 

 while occasionally species may occur which are perfectly constant 

 in color. Mr. Ashmead said that the wing pattern is of consider 

 able importance in the classification of the parasitic Hymenoptera. 

 In such genera as Perissopterus, Decatoma, Cerapterocerus, 

 Eusemion, Chiropachys, Habrolepis, and many others, the color 

 pattern of the wing is of generic value. Dr. Gill said that most 

 naturalists refused to use color in a generic sense, but some, like 

 Seebohm in the Turdidae, have used it extensively. Mr. Ash- 

 mead spoke of the eggs of birds as possessing specific characters. 

 Dr. Gill said that the characters used by oologists were of little 

 value. 



Mr. Ashmead said that the eggs of insects frequently possess 

 valuable characters, even of family rank, such as those of the 

 Pentatomidae and certain groups of Lepidoptera. Mr. Schwarz 

 referred to Rupertsberger's rare work on the classification of 

 insects from the eggs, and Dr. Dyar referred to Chapman's work 

 on the eggs of Lepidoptera. 



The third paper of the evening was by Mr. Schwarz, entitled : 



ON THE INSECT FAUNA OF THE MISTLETOE. 

 By E. A. SCHWARZ. 



Kaltenbach mentions four species of insects living upon 



Viscum album in Europe, viz., Psylla visci Curt, (exophila 



Frfd.), Aspidiotus visci Frfd., and two Cerambycid beetles of 



the genus Pogonocherus. The latter, however, have been bred 



