PHILIP P. CALVERT 349 



the right tubercle is fairly conspicuous, while the site of the left one is indi- 

 cated bj' a pit whose appearance suggests the possibility of its being the tu- 

 bercle invaginated. The three females from Cayuga, Guatemala, are less 

 mature than those from Costa Rica and may even be described as teneral; 

 one of them (May 8) has the tubercles similar to the condition described for 

 the Juan Viiias female, except that the left tubercle appears to be partly 

 everted from its pit, the other two have a pit in the place of each tubercle, 

 the margins of the pits more or less elevated as minute ridges. There is also 

 a posterior tubercle (pot) on the occiput near each lateral end. 



The distance between the apices of the inferior appendage of 

 the male is distinctly greater than that between the pits or tub- 

 ercles of the dorsal occipital surface of the female. It therefore 

 seems unlikely that there is any correlation here, but that those 

 apices rest, when pairing, farther cephalad on her head, probably 

 in the parocular groove (prs) between the eye and the lateral 

 ocellus of each side. In that case, a pair of shallow concavities 

 (fig. 15, dot') on the dorsal surface of the undivided basal part 

 of this appendage, situated just proximad to the l)ases of the 

 two branches, may receive the superior occipital tubercles of 

 the female. Whether the pressure on these tubercles is ever 

 sufficient to flatten them, or whether the eversion of the tubercles 

 is a concomitant of the age or development of the individual 

 female, and so would give the explanation of the differing condi- 

 tions noted in the specimens above described, are questions which 

 will probal:)ly reciuire observations on the living :nsects to deter- 

 mine. Taxonomically it is important to recognize the differing 

 state of the superior occipital tubercles in what appear to be 

 females of the same species. 



The vertex of the male is similar to that of the female. 



The occiput of the male has dorsal pits, but less pronounced than in the 

 female, but in no specimen before me has it either dorsal or posterior tubercles. 

 The rear of his head is not differentiated even to the extent of that of the 

 female. 



On examining some of the original material of Epifjomphus 

 llama Calvert from Bolivia, I found a paratypic female from 

 Chulimiani, December 3, 1898, sho\\ing two well nuu-ked post- 

 genal scars at about .35 mm. above (dorsal to) the level of the 

 articulations of the cardines of the maxillae with the head, and 

 about 1.05 mm. below (ventral to) the level of the mesal i)ro- 

 jection of each posterior eye-margin. I found that I could fit 



TRANS. AM. ENT. SOC, XLVI. 



