ARTHUR DEWITT WIIEDON 387 



Table Comparing Abdominal Dimensions in The Odonata 



Length of 

 synthorax 



Length of 

 abdomen 



Widest segment of 

 abdomen' 



Ratio of length 



of synthorax to 



length of 



abdomen 



ZYGOPTERA. 

 Agrioxixae: 



Agrion maculala 



Agrion augustipennis . 



Hetaerina americana . . 

 Lkstinae : 



Lesles rectangularis . . . 



Lestes euriyius 



Lestes vigilax 



Lestes unguiculatus . . . 



Lestes forcipatus 



Lestes uncatus 



PSKUDOSTIGMATINAE : 



Mecistogaster modest us 



Megaloprepus coerula- 



tus 



COKXAGRIONINAE I 



Lschnura verticalis . . . . 

 Enallngma caruncula- 



tum 



Coenagrion resolutum . 



ANISOPTERA. 

 Gomphinae: 



Ilagenius hrevistylus . . 



Gotnphus amnicola .... 



Gomphus fralernus . 

 Gotnphus cornutns . 



Ak.shnixae: 

 A nax Junius . 



Aeslina constricta . 



Epiaeshna heros 



CORDULINAE : 



Macromia illinoiensis . 

 EpicorduUa princeps . . 

 Tetragoneuria cynosura 



& 



5.5 

 7.2 

 6 



5.0 



5.3 



5 



5.3 



11 



4 



5 

 4 



14 



8 



10.5 

 9.5 



12 

 11 



12 

 9.5 



7 



5.5 



7 

 6 



5.6 

 5 



7 



9.5 



4 



4.5 

 4 



14.1 



10 



12 

 10 

 12 



7.8 



35 

 45 

 34 



40 

 38 

 37 

 29 

 28 

 29 



105 



20 



25 

 23 



58 

 36 



37.5 

 40 



48 

 48 



51 

 39 

 26.5 



34 

 35 

 27 



27 

 27 



70 



84.5 



22 



25 

 23 



60 



37.2 

 40 



49 

 47 

 56 



27.6 



d" 



2.79 



1.6 



1.6» 



1.5» 



1.5» 

 1.4» 

 1.5» 



3.9 

 1.9 



1.59 

 1 



5.9 

 3.2 



4.18 



3.2 



4.88 



3.8^ 

 4.5- 

 3.62 



2.9 



1.8 

 1.4 



1.69 

 1.69 

 1.69 



1.59 



1.2' 



1.59 

 1 



4.2 

 4.8 



8.2 



6.2 

 3.5* 

 6.2 

 4.7^ 



3.52 



1:6.4 

 1:6.2 

 1:5.7 



1:7.3 



1:5.5 

 1:5.6 

 1:6.5 



1:9.5 



1:5 



1:5 

 1:5.7 



1:4.1 

 1:4.5 



1:4.3 

 1:4.1 

 1:3.8 



1:6.2 



1:6 



1:5.3 



1:5.4 

 1:4.8 

 1:5.4 



1:10 



1:8.9 



1:5.5 



1:5.5 

 1:5.7 



1:4.3 



1:3.5 



'An exponent indicates the number of the segment measured. 



TR.VNS. AM. ENT. SOC, XLIV. 



