390 THE CANADIAN ENTOMOLOGIST 



In this table B. G. = British Guiana (Rockstone) and Tr. = 

 Trinidad (Baracon). Ten males from the former locality and six 

 from the latter were studied, so that the total number of fore or 

 hind wings was 20 from British Guiana and 12 from Trinidad. 



It will be seen from the table that in nearly every case the 

 prevalent number of veifts or cells is slightly greater in the British 

 Guiana specimens than in those from Trinidad. In the former, 

 e.g., the number of antecubital veins most often noted is 31 in the 

 fore wings and 21 in the hind wings, while in Trinidad specimens 

 the corresponding numbers are 27 and 20. Similarly in the case 

 of the postcubital veins, the prevalent numbers for the British 

 Guiana specimens are 22 and 26 for the fore and hind wings, respec- 

 tively, while for the Trinidad specimens they are 21 and 25. The 

 difference is too slight to be conclusive for any one table, but when 

 taken together the results seem to indicate fairly clearly a slightly 

 greater average complexity of venation in the British Guiana 

 specimens than in those from Trinidad. 



The Guatemala specimen is well above the average in com- 

 plexity of venation, but it is impossible to judge from a single 

 specimen how this form compares with the other two in this regard. 



In view of the apparent absence of distinctive structural 

 characters, it is improbable that there is more than one species 

 represented in this series. But there are at least two strikingly 

 different types of coloration characteristic of different localities, 

 and it, therefore, seems best to regard these as geographical races. 

 The Guatemala specimen, not being identical with either of the 

 South American forms may be considered for the present as the 

 type of a third race. 



The type locality of Burmeister's Aeschna reticulata is Surinam 

 and the British Guiana form may therefore be considered the 

 typical race. This is also suggested by the expression "viridi-flava," 

 which occurs in Burmeister's description quoted below. 



Staurophlebia reticulata reticulata (Burm.) 



Burmeister's description (Handb. der Ent., 1839, p. 837) is as 



follows ■} — 



"5. A. reticulata; viridi-flava, post mortem saepius fusca, tibiis 

 i ntus nigris. alarum venis nigris, cellulis fusco-limbatis, Long. 3M." 

 1. Kindly quoted tor me by Mr .E. B. Williamson. 



