76 



A. A. Girault: 



pl. I, fig. 7, $. I have never seen the original drawing. This nonagree- 

 ment of two drawings from the original necessitates a reiteration of 

 the fact that the antennae of toth sexes bear but a single ring-joint. 

 I have reexamined a number of females of T. lutea Girault. The latter 

 also bears a more or less distinct median sulcus on the mesothorax; 

 its color is bright orange yellow with a black band across the base 

 of the abdomen. None of the details of Krüger's figure of the adult 

 are correct. 



9. The Widely Distributed Genera of the TricJiogrammatidae. 



Of the known genera of this family, now numbering thirtynine 

 (two of which are as yet known in manuscript only) the following are 

 common toEurope, North America and Australia, three widely separated 

 countries : Oligosita Haliday and Trichogrammen Westwood. The former 

 has numerous species native to Australia and America and also se- 

 veral to the island of Ceylon. Trichogramma has species native to South 

 America and a supposed species from Ceylon; it also has a species 

 native to the Sandwich or Hawaiian Islands in the Pacific. Since 

 the family has been more thoroughly explored in North America and 

 Australia than elsewhere, we should not be surprised to find more genera 

 common to both an such is the case. These genera are common to the 

 two widely separated countries: Oligosita Haliday, Trichogramma 

 Westwood, Brachistella Girault, Aphelinoidea Girault, Tumidiclava 

 Girault, Abbella Girault, TJscana Girault and Ufens Girault. Tricho- 

 grammatoidea Girault is common to Australia, Java and Africa; the 

 genus Japania to China and Australia. The new genera found in 

 Australia appear to be peculiar to it as does also Pterygogramma 

 Perkins. 1 ) 



These are very striking facts. To one who experiences them for 

 the first time a number of questions at once arise. How did these genera, 

 though they may be thousands of years old, get first hold on lands 

 so far apart and so effectually isolated one from the other. One of 

 the ideas which Struck me immediately was that they arose indepen- 

 dently in each country. There is only one other alternative and that 

 is that they all had a common origin and subsequently became widely 

 distributed. But distributed how? We may argue that if a genus 

 can arise from a common stock at one portion of the earth there is no 

 reason why it should not arise at the same time or subsequently in 

 another; but if an argument of that kind is made one must be able to 

 support it with facts and after reflection I am unable to do this. Nor 

 in my extensive reading have I ever seen any facts in favor of it. If 

 we argue that the same genera can originate independently in different 

 countries at different times we must also admit that both 1 arger 

 and smaller groups can do so. But if so originating why are they so 

 ciosely alike their components. On this supposition, how can we explain 



J ) On the other hand North America appear8 to have not more than two 

 genera peculiar to it. 



