160 BRUES. 



ble a spider's web or thistle seed drifting along. Indeed, when 

 I first saw them it was hard to believe that they were really 

 alive. Bittacomorpha seems to have developed its protective 

 coloration along the same lines as the zebra among the verte- 

 brates ; it is rendered invisible not only by the fragmentary 

 distribution of color, but by the neutral gray color produced by 

 the visual blending of the black and white. 



From the description of Bittacomorpha Sackenii by Von 

 Roeder, it seems that this species does not possess any dilata- 

 tion of the metatarsi. It would be very interesting to see if 

 there is any abnormal development of the tracheal system in 

 this species, but unfortunately I have been unable to procure 

 specimens. The specimens examined were given to me by 

 Dr. Wm. M. Wheeler, to whom I feel greatly indebted for 

 many kind suggestions. 



