204 Journal New York Entomological Society. f^'o'- ^^ 



Mr. Leng stated that the work on the Elateridae in the local collection 

 would be taken up the following Saturday. 



Under scientific discussion Mr. Grossbeck spoke on the abundance in 

 this locality the past September of the migratory moth, Aletia argillacea Hbn. 

 This discussion was participated in by several members, all reporting the 

 insect very abundant and records were obtained as far distant as Providence, 

 R. I., and Buffalo, N. Y. 



Dr. Lutz spoke of some examples of mimicry which he had observed in 

 a recent trip to South America. While in British Guiana, S. A., he saw what 

 he supposed to be brown ants running upon some leaves. Upon capturing 

 the insects, however, and examining them he found that they were a species 

 of Diptera. No ants were found in the immediate vicinity but some were 

 obtained in the forest under the leaves, while the flies had been captured on 

 leaves in an open area. He questioned very much whether this could be con- 

 sidered a case of mimicry. On another occasion he observed on the leaves 

 of an acacia what appeared to be a number of Membracids or Aphids each 

 attended by an ant. On capturing some and examining them more closely 

 he discovered that they were a species of Membracidae with the branching 

 appendages of the pronotum so developed as to closely resemble an ant. So 

 close was the resemblance that when the insects were being mounted the 

 one mounting them attempted to separate the ants from the insects. 



Dr. Lutz read from a paper by Professor Poulton, in which he discussed 

 the large number of forms of Membracids with the thoracic appendages 

 developed in a similar manner. 



Dr. Crampton made some interesting remark upon the recent South 

 American trip. They had gone down through the West Indies and stopped 

 at several points, including Martinique and St. Lucia, making intensive 

 studies and obtaining a conception of the obvious insect and invertebrate 

 fauna. From thence he went into British Guiana. For the first i8o miles the 

 country with its forests was found to be very flat. Then hills arose to a 

 plateau of 1,300-1,400 ft. altitude. L^p the rivers and through the forests 

 very striking examples of Cryptical coloration in Orthoptera, Hymenoptera 

 and a few Lepidoptera were noted. The country rose gradually to an altitude 

 of 1,600 ft. near the borders of Brazil, where the cliffs rose 5,000-6,000 ft. 

 Much material had been collected to be worked over. From the conditions 

 observed the following general facts were noted in a given habitat: (i) In 

 forests of the same type on different slopes certain organisms of the same 

 type occurred; (2) In any particular forest some forms characteristic of and 

 peculiar to that altitude occurred; (3) Irrespective of altitude in a given 

 river system certain characteristic types occurred. 



Mr. Leng asked concerning the distribution of any tiger beetles noted. 

 Dr. Crampton said that a species had been observed on the coast that had 

 not been found on the Amazon side of the mountains. 



Mr. Leng stated that a similar condition might be inferred from the 

 distribution of Cychnis violaceus in Georgia. This species was described by 



