494 NEW YORK STATE MUSEUM 



Tetragoneuria cynosura Say 



Dog-tail 



1839 L ibe 11 ula cynosura Say, Acad. uat. sci. Phil. Jour. 8:30 

 1839 Ep op h thai mi a lateralis Burmeister, Handb. eut. 2:847 



1873 Cordulia cynosura Hagen, Bost. soc. nat. hist. Proc. 15 : 271 



1861 Cordulia lateralis HagenjSynopsisNeur.N. Am. p. 139 (description) 

 1893 Tetragon euri a cynosura Calvert, Am. ent. soc. Trans. 20:252 



(descriptiou) 

 1895-97 Te tr a g o n curia cynosura Calvert, N. Y. ent. soc. Jour. 3:46 

 and 5 : 93 (listed from Ithaca, Lake George, Black Rock) 

 Tetragoneuria cynosura Kellicott, Odon. Ohio, p. 89 (description) 

 1900 Tetragoneuria cynosura Williamson, Dragon flies Ind. p. 311 

 1890 Epitheca cynosura (nymph) Cabot, Immature state Odon. pt 3, p. 28 



This species, which has hitherto been recorded from but few localities 

 within the state, is likely to be found in most large ponds in central and 

 western New York. I have but one additional locality to record. I 

 have received specimens from Prof. Herrick collected at Canandaigua. 



I have not united with this species semiaquea Burmeister, notwith- 

 standing that I think them one species showing racial variations, because 

 there is no difficulty, so far as I have observed, in separating the imagos 

 on the basis of the color distinction long in use, and because my bred 

 nymphs do not agree very closely, and I have not had time for the study 

 of a long series of these nymphs. I would call attention, however, to 

 a fact indicating either that they will probably be found to intergrade, or 

 that some one has made an error or mixed his specimens. Cabot de- 

 scribed a longer and a shorter type of nymph of the straight-spined 

 form : the one with the longer spines was bred and was T. cynosura; 

 the one with the shorter spines was referred to T. s e m i a q u e a on sup- 

 position. From the shorter spined of my two with straight spines I bred 

 abundantly in Illinois the typical T. cynosura. I have observed, 

 however, that there is considerable variation in the length of these 

 spines: ther^ seems to be much less of it in their direction. While it 

 seems likely that T. semiaquea will eventually rank as a race of T. 

 cynosura, pending farther study, I have listed them separately 

 here. 



Tetragoneuria semiaquea Burmeister 



1839 Libellula semiaquea Burmeister, Handb. ent. 2 : 858 

 1842 Cordulia complanata Rambur, Ins. Neur. p. 145 



1874 Cordulia semiaquea Hageo, Bost. soc. nat. hist. Proc. 16 : 360 



1861 Tetragoneuria semiaquea Hagen, Synopsis Neur. N. Am. p. 140 



(description) 

 1893 Tetragoneuria semiaquea Calvert, Am. ent. soc. Trans. 20 : 252 

 1895-97 Tetragoneuria semiaquea Calvert, N. Y. ent. soc. Jour. 3 : 46 



and 5 : 93 (listed from Ithaca, Baldwinsville, Black Rock) 



