XCVlll 



Mr. Klages a number of years ago, a series of wliich is here 

 shown. No doubt H. a. estebana greatly resembles Protogonius 

 hippona lilops on the wing, as I noted in Trinidad that the 

 Heliconius there, H. numata ethilla, flew with and greatly 

 resembled while in flight Protogonius hippona ochraceus. 

 While watching these flights a most interesting fact was 

 noted. The Protogonius was observed, while sailing along 

 overhead, to present the upperside colouring. Earlier in 

 Venezuela I noted the same phenomenon with lilops at San 

 Esteban, and have since proved that how this happens is that 

 the cryptic colouring of the underside is composed of partly 

 transparent scaling which is also set more openly instead of 

 very closely as on the upperside. The result is that the 

 colouring of the upperside against the light shows through, 

 and thus on the wing the Ithomiine appearance is complete 

 when viewed from above or beneath. 



" The story of how I discovered that Protogoiiius was trans- 

 parent is as follows. In November 1920 I was in Trinidad, 

 and while collecting on one of the hillsides above St. Ann's 

 Valley, I saw Protogonius ochraceus below me sailing about 

 with outstretched wings. The inference was then made that 

 if one was below instead of above one would see the dead 

 leaf-like underside. In December I visited Venezuela and in 

 the San Esteban Valley I noted that Protogonius lilops flying 

 along in front of me exhibited the upper side. Several speci- 

 mens of this species were subsequently caught but always 

 fluttering near the ground and no more was thought of the 

 incident. In late December a return was made to Trinidad' 

 and on January 1st, 1921, when walking along the Ariapita 

 Koad in St. Ann's Valley a number of Protogonius ochraceus 

 were observed from below while floating around a tall bush 

 of from 12-15 ft. These specimens very clearly showed the 

 upperside colouring, and the thought came that these butter- 

 flies were flying ujiside-down. At the end of the month I 

 left for England and forgot the incident of the upside-down 

 Protogonius until just recently, when I was arranging the 

 mimetic groups for exhibition, the recollection of the Proto- 

 gonius again came to mind. I then held specimens over my 

 head to try and understand how it was I saw the uppersides 



