BY R. J. TILLYARD. 315 



species, their life-histories, larval forms, habits and imaginal 

 characteristics, and to supplement these with dichotomous keys 

 and plates shewing parts used in classification. 



I am indebted to Dr. Laidlaw for examining the types of 

 Synthemis in the British Museum; to M. Rene Martin, of Paris, 

 for knowledge of the types in the de Selys collection, for the 

 information quoted above about S. miranda, and above all for 

 his excellent work on the Corduliince; and to Dr. Ris, of Rheinau, 

 Switzerland, for many valuable hints on field-work, and for his 

 great interest in, and kindly criticism of my new discoveries. 



Material studied. 



Imagines. — My earliest captures were forwarded to M. Kene 

 Martin for identification, and he was kind enough to return, with 

 them, some named specimens of his own, which had been com- 

 pared with de Selys' types. These were specimens of the three 

 closely allied species, .S'. brevistyla, S. guttata, and S. virgula. In 

 my collection there are two hundred and thirty set specimens of 

 the genus, comprising long series of all the commoner ones. All 

 these have been examined carefully for variation. Besides 

 these, I have examined another hundred or moi'e papered speci- 

 mens, which have since been sent out to my various correfspon- 

 dents. Of the rare species, J possess two males and three females 

 of *S'. nigra, two males and one female of S. claviculata, and two 

 males of jS. olivei. 



I have never seen the unique female type of S. miranda, but 

 fortunately it is well figured in M. Martin's " Cordulines," and 

 de Selys' own description is also available. The series of *S'. 

 primigenia possessed by Prof. Forster of Berlin, is also inacces- 

 sible; but I have Forster's careful description, and a good figure 

 in Martin's work above-mentioned. 



Larvce. — During the past two years I have collected and reared 

 a considerable number of larvae, at various stages of growth, of 

 <S'. ev.stalacta, S. macrostigma, and S. guttata. Over fifty of these 

 are preserved in my collection. Of S. regina I have only five 

 specimens, and of S. flavoterminata a dozen. 



