Calvert : Odonata of the Neotropical Region. 223 



137. Neocordulia volxemi. 



(Plate VII, Figs. 132, 133). 



Gomphomacromia volxemi Selys, Bull. Acad. Belg. (2) xxxvii, p. 21. 1874. 

 Martin, Coll. Zool. Selys Cordulin. p. 55, fig. 72 (venation). 1906. 

 Neocordulia volxemi Selys, Compt. Rend. Soc. Ent. Belg. 1882, p. clxix. 

 Kirby, Cat. Odon. p. 53. 1890. 



This species has hitherto been known only from the female sex. M. 

 Martin has again referred it to Gomphomacromia after de Selys had re- 

 moved it to the more lately established Neocordulia. M. Martin 

 remarks, /. c, " Cette espece forme le passage entre les Neocordulia 

 et les Gomphomacromia : si on tient compte de l'ecaille vulvaire courte, 

 elle devrait etre classee avec les Neocordulia ; si, au contraire, on 

 remarque qu'elle n'a, apres un rang de 2 ou 3 cellules d'abord, qu'un 

 seul rang de postrigonales, sa place est avec les Gomphomacromia.'" 

 Yet the figure accompanying M. Martin's text, fig. 72, shows two 

 rows of posttriangular cells from triangle almost to the hind margin of 

 the front wings and for five cells beyond the triangle on the hind wings, 

 when the number of rows increases — in noplace a single row. De 

 Selys also gives no hint that volxemi has other than "deux rangs pos- 

 trigonaux " (/. c. 1882). There seems to be no reason, therefore, so 

 far as the posttriangular rows are concerned, for excluding volxemi 

 from Neocordulia?' 1 



9. Two females from Chapada in the Museum of Comparative 

 Zoology agree quite well with de Selys' description and M. Martin's 

 figure, except that the abdominal appendages are longer than 10, more 

 than half as long as 9. The vulvar lamina, the length of which is not 

 given by the preceding authors, reaches to the level of one-third the 

 length of the sternite of 9, which latter bears two small style-like 

 processes at the level of the tip of the vulvar lamina. 



cJ*. Two males in the same Museum, one labeled Chapada, Decem- 

 ber, the other simply "Brazil," are very probably of this species. 

 They have the face and lips greenish-yellow, becoming brownish, with 

 some metallic-blue reflection on the anterior surface of the frons and 

 on the vertex. Occiput dull pale brown or yellow. 



Thorax brilliant metallic-green, the sutures and most of the ventral 

 surface pale brown. 



32 An error which has crept into Prof. Needham's work " A Genealogic Study of 

 Dragon-fly Wing Venation " (Proc. U. S. Nat. Mus. xxvi, pp. 703-764. 1903) may 

 also be corrected here. Fig. I, pi. xlii, given as the wings of Neocordulia androgynis, 

 is not that of a Neocordulia at all, but of something close to Dorocordulia. 



