PHILIP P. CALVERT 323 



"~ ^'^tu 



THE COSTA RICAN SPECIES OF EPIGOMPHUS AND THEIR 



MUTUAL MATING ADAPTATIONS 



(ODONATA) 



BY PHILIP P. CALVERT 



University of Pennsylvania, Philadelphia, Pa. 

 (With Plates XIII, XIV and XV) 



Abstract 



This paper increases the number of Costa Rican species of Epigomphus 

 from five to seven and adds data on distribution, colors and structure of all 

 of them. 



Adds data on the variation of the generic characters. 



Annoimces a liitherto undetected secondary sexual character in the tarsus 

 of the tliird leg of the males, which is also a new generic character. 



Makes knowTi one liitherto unknown species (E. subsimilis) and the pre- 

 viously undescribed female of one other species {E. tumef actus) . 



Attempts a correlation of the form of the heads of the females and the male 

 abdominal appendages as concerned in the act of mating and figures the 

 heads of the females more fuUy than ever before. 



Contents 



Page 



Historical Introduction 323 



Distribution of Epigomphus in Costa Rica 325 



Generic Characters of Epigomphus 327 



Synopsis of the Species and Xotes on their Colors, Vulvar laminae, etc. 



331 



IVIutual Mating Adaptations 338 



Explanation of Plates 353 



Historical Introduction 



The "sous-genre Epigomphus Hagen" was first published by 

 de Selys in 1854 in the Sijnopsis des Gomphines, one of those joint 

 works by the Belgian and the Prussian writers in which it is often 



TRANS. AM. ENT. SOC, XLVI. 



