350 COSTA RICAN EPIGOMPHUS (oDONATa) 



the appendages of a male from the same locaUty and date to the 

 head of this female so that the tips of his superior appendages 

 rested in these postgenal scars; with the result that each branch 

 of his inferior appendage came to lie in the parocular groove of 

 the same side of her head, laterad of the ocellus but mesad of 

 the antenna, the tip of each branch reaching cephalad to the 

 superior surface of her frons, the superior anteapical process of 

 each branch being received into the depression behind each of her 

 antennae, the antenna being enclosed caudad by the concavity 

 between the tip of the branch and that process. I was unable 

 to detect any superior ocular scars on her head. Her superior, 

 or dorsal, occipital tubercles are received by shallow concavities 

 at each side of the dorsal surface of the base of his inferior append- 

 age. 



The position of the postgenal scars in E. llama female is thus 

 much lower than in any of the Costa Rican species studied. 

 This more ventral position is probably due to the more slender 

 form of the superior appendages of the male llama, since their 

 absolute length (2.10 mm. in dorsal view) is no greater than that 

 of the same appendages of E. suhohtusus. The inferior appendage 

 of llama male also reaches farther cephalad on the female's head, 

 apparently, than in any of the Costa Rican species. Here again 

 the slenderness of the branches of this appendage is partly re- 

 sponsible for the difference, although the absolute length (2.1 

 mm. in ventral view) is greater than that of suhohtusus (1.68 mm.) 



It may be that relations similar to those of E. llama exist be- 

 tween the male appendages and female head in E. ohtusus Selys 

 and E. hylaeus Ris, also of the South American continent.^- The 

 Brazilian E. paludosus has the superior appendages of the male 

 much shorter (1.62 mm.), so that probably they can not reach 

 so far ventrad on the rear of the female's head; his inferior ap- 

 pendage (2.0 mm. long) is not so different from that of llama and 

 may take a similar position on her head. 



32See the figures of E. llama, Ent. News, xiv, pi. viii, figs. 2 and 7 (1903), 

 and Archiv f. Naturges., 82 Jahrg., Abt. A, 9 Heft, p. 1.52, figs. 99, 100, 

 (1918), and for obtusus and hi/lrieus in the latter, p. 151, figs. 96, 97, and p. 

 1,54, figs. 102, 103. 



