^88 THE CANADIAN ENTOMOLOGIST. 



Ohio very constant in size: abdomen, ^ 27 mm., ? 27.3 mm; hind 

 wing, ,f 19.9 mm., ? 21 mm. The postocular spots were found to vary 

 from long, narrow, wedgy, connected, to short, ovate, disconnected. 

 Other markings usually employed in descriptions were found to vary 

 greatly. The superior appendages of the male were found to be constant 

 in length compared with the tenth segment, and in pattern. 



GompJms fratenius and G. externus were studied by B. D. Walsh 

 and the details and comparisons published in the Proceedings of the Ent. 

 See. of Philadelphia^ Volume II. In regard to the former he says there 

 i> no slender thorn in the vertical vesicle of the female. These the 

 author found always present, to be long and slender, and to vary in 

 colour between wholly black and wholly yellow. The yellow vitta on the 

 hind femur of the female, claimed by Walsh to be a distinguishing 

 character, was found to be present in about one-half the individuals and 

 wholly wanting in one-fourth. In externus the spine of the vertex is 

 present. It is a short, dark cone. The vitta on the posterior femur 

 varies much as in fraternus. The conspicuous vitta on the ninth 

 abdominal ring of externus, male, varies as follows : In about nine 

 cases in ten it is normal ; /. e., extends the entire length of the segment, 

 broad, and orange in colour ; one in ten has it faint and narrow. An 

 occasional male o^ fraternus has a similar faint vitta on nine. 



In size both species were found to be exceedingly constant and 

 larger than the measurements given by Baron de Selys. Exterjius : 

 Abdomen, (^ 40.3 mm. (average of ten); $ 39.3 mm. (average of three). 

 Hind wing, S 32-5 mm; ? 34 mm. Fratenius: Abdomen, $ 36.8 

 mm. (average of ten); ? 37.2 mm. (average of ten). Hind wing, ■$ 

 30.9 mm.; ? 31.5 mm. 



Other discrepancies were pointed out in Walsh's description of the 

 female of externus (consobrinus) and a question raised as to the accepted 

 conclusion that consobrinus, Walsh, is after all a synonym of externus, 

 Selys. 



6. A second paper was read by Dr. Kellicott, " On the Occurrence 

 of Dragonflies in Ohio in 1896." The seasons of 1894 and 1895 were 

 those of extreme drought. Ponds and streams went dry for weeks over 

 wide areas. A dearth of Odonata was looked for in 1896. This has not 

 been the case; on the contrary, there has been an extreme abundance. 

 No species heretofore known to abound has been missed, whilst several not 

 before noticed have occurred, widespread and numerous. It would 



