282 FREDERICK KNAB. — SOME NEW NEOTROPICAL SIMULIIDAE. 



no doubt to select a suitable place for oviposition. The female SimuUum approaches 

 the current quite near and selects a spot on a boulder or stone at the side of the big 

 current, but just covered by a thin film of water. She settles and holding on with her 

 claws she lays as fast as she can, sticking her eggs to the stones in little groups of 

 6 to 20. It happens that sometimes she is swept away by the current, but this does 

 not seem to disconcert her in the least, as immediately afterwards she may be seen 

 hovering over the same place. As many as five females were observed hovering over 

 the same place at a time. Females caught in these places and put into tubes continued 

 ovipositing, sticking their eggs to the glass very easily. 



Incubation of egg : Eggs laid in a glass tube hatched after five days. 



Habits of larvae : The larvae are found in the strongest current, attached to 

 almost vertical walls of boulders ; sometimes they are found on sticks or leaves in 

 the strong current. 



Pupae : Found in same places as larvae. 



Habits of adults: Cons ideiin the number of larvae seen in the stream, there 

 are comparatively few adults about. The writer has never been attacked by them. 

 All that were taken feeding occurred inside the ears of horses or mules. 



Note.- — The " type " and paratype specimens have been returned by Mr. Knab 

 to the collections of the Wellcome Bureau of Scientific Research, London. Other 

 paratypes are held in the collections of the U.S. National Museum, Washington, 

 D.C.— M. E. MacGREGOR. 



