Petersen, New and little-known species of Ephemerida fr. Argentine. 337 



Fig. 5. Thraulus bomplandi. 

 Fore and iiind wing (the latter more magnified than tte former). 



are held up to the light. Subcosta , radius and subradius with 

 a small thickened part half way up the wing , more noticeable 

 in the subcosta and subradius. Fore and bind wings dark reddish 

 brown clouded at the base. 

 Length 8,5 mm ; wing 

 8 mm. 



The description is made 

 from a single male, preser- 

 ved in alcohol and collected 

 at Bompland. The exam- 

 pel has lost its setae , the 

 greater part of the forceps 

 limbs and all its legs with 

 the exception of one bind 

 femora and tibia. It is a 

 fine looking and an easily 

 recognized species. The ^, ^% ^- Thraulus bomplandi. 



? j. 1, ^'^^ "^^ö lorceps limb and the penis, seen 



species seems to have a from the underside. Penis, seen from above. 

 great likeness to Thraulus 



laetus Eat., but it differs especially in the shape of penis, in the 

 colouring of the wingroots and in the thickening of the subcosta, 

 radius and subradius , so I have no hesitation in describing it. 



6. Thraulus Haarupi n. sp. 



Female , in alcohol. Head brown ; eyes black. Thorax 

 yellowish brown, paler on the dorsum and with a fine longitudinal 



Deutsehe Entomol. Zeitschrift 1912. Heft III. 23 



