1914.] NATURAL SCIENCES OF PHILADELPHIA. 373 



ON THE OKTHOPTERA FOUND ON THE FLORIDA KEYS AND IN EXTREME 



SOUTHERN FLORIDA. II. 



BY JAMES A. G. REHN AND MORGAN HEBARD. 



During the month of July, 1912, the authors undertook a careful 

 field examination of the Florida Keys and the adjacent mainland in 

 order to complete their studies in the Orthoptera of the subtropical 

 area of southern Florida. ^Material procured by field work under- 

 taken by the junior author in January and February, 1903 and 1904, 

 and in March, 1910, as well as small collections made at Miami 

 during the summer of 1903 and at that locality and Key West in 

 November, 1911, have already been studied.^ The supplementary 

 results obtained from the present collection, when compared with 

 the material of the two previous papers noted above, afford a very 

 complete knowledge of all but the scarcest species of the Orthoptera 

 of this region. A number of species of tropical origin are there so 

 scarce and so difficult to find that our knowledge of them is based 

 on the single or very few specimens taken; such species can only 

 be fully studied by a resident or through definite search for these 

 forms alone. We feel satisfied, however, that the present paper 

 gives the final results of a very careful general examination of the 

 region under consideration. 



The recent summer work indicates several important facts. The 

 families Mantidse, Acrididse, and Tettigoniidae are shown to be 

 severely affected in winter by the cold, the Acrididse the least of the 

 three families. Almost all of the fairly plentiful or abundant species 

 • are to be found in greatly increased numbers in the summer, but the 

 scarce or very rare species are in the great majority of cases quite as 

 difficult to find in the summer as during the winter. Certain species, 

 particularly some of those belonging to the Acrididse and Tetti- 

 goniidae, which are numerous or very abundant during the summer, 

 are wholly absent in the winter. The following table- will indicate 

 the comparative abundance of forms as found in midsummer. 



1 Proc. Acad. Nat. Sn. Phila., 1905, pp. 29-.5.5; Ibid., 1912, pp. 235-276. 



2 Thij5 table .should be compared with that already given (Pruc. Acad. Nat. 

 Sci. Phila., 1912, p. 235) which shows the comparative abundance of forms as 

 found just before the appearance of the spring forms. 



