June, 1915.] Proceedings of the Society. 159 



where so many strains meet that many local forms, confined to small areas, 

 result. Mr. Avinolf closed by describing the tortuous line by which the 

 Thibetan faunal province is surrounded by paltearctic and other regions, and 

 the variety of forms collectable in a single day on its mountainous border, by 

 working at different elevations. 



His remarks were discussed by Dr. Lutz, who pointed out the different 

 opinion expressed by Schimper in regard to a division of the Siberian forest 

 region, and by Mr. Angell in regard to Coptolabriis and other Carabid genera. 



Dr. Riley being called on by the chairman, spoke briefly of the medical 

 phases of entomology. 



Dr. Lutz delivered his paper on distribution of West Indian spiders, 

 abridged on account of the late hour, calling attention to the muscvun collec- 

 tion identified by Nathan Banks and the great additions to the Petrunkevitch 

 catalogue resulting from museum expeditions. Notwithstanding the contrary 

 opinion derived from study of other groups, he said he could find in the 

 spiders no definitely distinct West Indian fauna, nothing but an admixture 

 of continental forms, resulting from movements of species between the islands 

 themselves and between them and the mainland. Peculiar forms, as far as 

 they exist, are all of ancient types, and are evidently relics of past times, 

 which are being replaced by more recent forms, principally from the north, 

 though the extreme southerly islands naturally show more South American 

 affinities, from their geographical proximity. 



In the discussion that followed with Messrs. Avinoft' and Schaeft'er, Dr. 

 Lutz showed how unnecessary theoretical land bridges were, and even ridicu- 

 lous, for, if all the known cases of relic distribution in distant regions, like 

 Madagascar and South America, were sought to be thus explained, the ocean 

 would be filled with bridges ; and how ample the millions of years in Tertiary 

 time for the movements he advanced as explaining the distribution from the 

 mainland. 



Mr. Davis exhibited the specimens on which he based his latest supplement 

 to the list of Macrolepidoptera of Staten Island, which he stated had now 

 reached 673 species, of which 85 were butterflies, calling attention particularly 

 to an intermediate specimen of Papilio which was neither turnus nor glaucus, 

 though somewhat nearer to the latter; and to the spring form of Attacus luna. 



Referring again to the insects caught in the Adirondacks while with Mr. 

 Shoemaker, he also read a letter from Dr. J. M. Aldrich, in which the botflies 

 he caught were stated to be probably the first adults of Cephenomyia ever 

 caught in the western hemisphere. 



This genus is known in the Old World to live as larvas under the skin 

 of deer. Mr. Davis said his specimens were caught in open spots among ever- 

 greens, loafing lazily on vegetation. 



