Calvert : Odonata of the Neotropical Region. 143 



The specific name proposed is an anagram from the name of the 

 collector with a terminal a added for euphony. 



Argia thisma vies with A. bipunctulata Hagen of North America as 

 the smallest known species of the genus. It closely approaches the 

 description of A. lilacina Selys, also of Brazil, which latter, however, 

 is stated to have the abdomen cT 26 mm., hind wing c? 19-20 mm., 

 rear of the head yellow, a yellowish lilac antehumeral band almost 

 forked above, the black line on the second lateral thoracic suture in- 

 complete, the first seven abdominal segments clear blue violet, 3-7 

 with a thick terminal black ring. 



In spite of its small size A. thisma preserves a character of the genus 

 which on a priori grounds might have been expected to disappear, 

 i. e., the origin of M 2 (nodal sector) is still as far distad as the sixth 

 postnodal on the front wings and the fifth on the hind. Stated in 

 another way, enough postnodals are retained to permit of the persis- 

 tence of this numerical relation to the point of origin of M 2 . (Cf. 

 Biologia Centr. -Amer. , Neur. , p. 376 under Argia llagma.) 



54. Argia jocosa Hagen. 



Habitat: — Colombia, Onaca, in Dept. Magdalena, August, by H. 

 H. Smith, 1 cP. Carnegie Museum, Pittsburgh. 



55. Argia cupraurea Calvert. 



Argia cupraurea Calvert, Biol. Centr. -Amer. Neurop., pp. 85, 371, pi. iv, figs. 24, 

 42, 1902, 1907. 



Habitat : — Venezuela, La Guaira, by Lyon and Robinson, July 4, 

 1900, 1 d\ July 27, 1 $ ; San Julian, July 20, 1900, by M. W. Lyon, 

 Jr., 1 c?. U. S. National Museum. 



56. Argia orichalcea. 



Argia orichalcea Hagen, Bull. Acad. Belg. (2), xx, p. 408, 1875. Calvert. Biol. 

 Centr. -Amer. Neurop., pp 71, 86, 1901. Hagen and Calvert, Bull. Mus. Comp. 

 Zool. xxxix, p, 113, pi. 1, figs. 7, Ja (apps. $ ), 1902. 



6\ The original description of this species states, abdominal seg- 

 ments " 3me-6me avec une tache basale bleu fonce occupant presque 

 la moitie au-dessus " and implies that segments 8 to 10 are as in cuprea, 

 i. e., 8 black, narrowly pale blue at base, 9 and 10 greenish-blue 

 above. In the Biologia, I. c. I have given these markings as dis- 

 tinguishing orichalcea from oenea, stating, however, that I had not 

 seen orichalcea. Material from Bonda, Colombia, listed below, 



