PSYCHE. 



NEW NORTH AMERICAN ODONATA. 



BY ALBERT 1'. MORSE. VVELI.ESI.EY, MASS. 



C:ilveit, in his catalogue of tlie 

 Odoiiatci of Phiiadelpliia, lists the 

 following eight species of E}iallagma 

 from the northeastern States : aspcr- 

 snm^ civile^ divag'aiis, durum, exsu- 

 lanSf hageni, poll tit um, signal urn. 

 Other forms reported by various 

 authors from this district are : fl«- 

 ncxiini, ebrinin, traviatiim. To these 

 Calvert (Ent. news, Oct. 1S94) adds 

 doubledayi ; and in the following 

 pages two more are added, making 

 fourteen species of the genus to be 

 found in New England. One of the 

 latter (and two additional new species 

 described here) is found in Nevada 

 also. A note is added on the diag- 

 nostic diflerences of aspersii7n and 

 trav/afiim. Descriptions are also pre- 

 sented of an Ophiogomphus from the 

 eastern States, a Tetragoneurla from 

 Massachusetts and a case of variation 

 in venation in Erythromma conditian. 



In consideration of the fact that the 

 species of EnaUagma approach each 

 other so closely that sketches of ana- 

 tomical details are almost imperativelv 

 demanded, the author intends to pre- 

 sent in a subsequent paper diagnostic 

 drawings of all the New England 

 species and of as many other Norlh 

 American forms as it may be possible 

 to obtain. 



Being a firm believer in the desira- 

 bility of assembling the types of closely 

 allied species in order to facilitate 

 comparative study, the writer proposes 

 to ultimately present the types here 

 described to the Hagen collection in 

 the Museum of Comparative Zoology 

 at Cambridge, Mass. 



EnaUagma minusculurn, sp. nov. 



Abd. 20 mm., hind wing, 14-15 mm. 

 Cuneiform post-ocular spots small, more 

 or less rounded. Posterior lobe of prono- 

 tum black, unspotted, margined with yellow; 

 anterior lobe with pale transverse band. 

 Thorax with the following black: a wide 

 mid-dorsal stripe, widest in front; a wide 

 humeral (wider than pale ante-humeral) 

 stripe, wide.st below, expanded on and just 

 behind its crossing of the humeral suture. 

 Abdomen black as follows: dorsum of i, 

 divided by an apical spot of blue or purple; 

 posterior half of 2, third of 3, two-fifths of 

 4, half of 5, three-fifths of 6, four-fifths of 

 7, and all of 10; 8 and g blue. 



Superior appendages half as long as 10, 

 in profile broader than long, equalling in 

 depth (on expanded portion) one-half that 

 of 10, very broadly bifid, the posterior 

 margin shallowly excavate, the lower 

 branch projecting a little beyond the upper, 

 much expanded, laminate, directed down- 

 ward and inward; the upper branch one- 

 third as broad, directed slightly upward, 

 and bent inward claw-like. Inferior appen- 

 dages equal in length to the superior, Ijroad 

 at base, narrowed and tapering in the 



