1914.1 



NATURAL SCIENCES OF PHILADELPHIA. 



375 



Principal Localities and Dates of Examinations. 



Miami, Dade Dounty, Florida. — January-February, 1903, (H.); 



Januarj^-February, 1904, (H.); March, 1905, (Caudell); March 



1910, (H.); November, 1911, (Englehardt). 

 Homestead. Dade County, Florida.— March, 1910, (H.); Julv, 1912, 



(R. & H.). 

 Detroit, Dade County, Florida.— July, 1912, (R. & H.). 

 Jewfiph, Monroe County, Florida.— July, 1912, (R. & H.). 

 Key Largo, Monroe County, Florida. — March, 1910, (H.); July, 



1912, (R. & H.). 

 Long Kev, Monroe County, Florida. — March, 1910, (H.); July, 



1912," (R. &H.). 

 Key Vaca, Monroe County, Florida.— March, 1910, (H.); July, 



1912, (R. & H.). 

 Boot Key, Monroe County, Florida.— March, 1910, (H.). 

 Big Pine Key, Monroe County, Florida.— July, 1912, (R. & H.). 

 Key West, Monroe. County, Florida. — January, 1904, (H.); March, 



1905, (Caudell); March, 1910. (H.); November, 1911, (Engle- 

 hardt); July, 1912, (R. & H.). 

 Garden Kev, Dry Tortugas. Monroe County, Florida. — July, 1912, 



(R. & H.). ' 

 Bird Key, Dry Tortugas, Monroe County, Florida. — July, 1912, 



(R. & H.). 

 Loggerhead Key, Dry Tortugas. Monroe County, Florida. — Julv, 



1912, (R. & H.). ■ ' 



Relative Value of Tropical Element. 



In this region the truly tropical element is shown by the following 

 species : 



Prolahia arachidis (Yersin). 



Ischnoptera rufescens (Beauv.). 



NeoblatteUa detersa (Walk.). 



Supella supellectiliurn (Serv.). 

 *Ceratinoptera diaphana (Fabr.). 



Leurolestes pallida (Brunn.). 



Blaherus atropos (StoU). 



Holocompsa nitidula (Fabr.). 

 *Plectoptera poeyi (Sauss.). 



*Mantoida maya S. & Z. 

 *Aplopus mayeri Caudell. 

 *Stilpnochlora margineUa (Serv.). 



*Oligacanthopus prograptus R. 

 Gryllodes sigillatus (Walk.). 

 *Cyrtoxipha gundlachi Sauss. 

 *Orocharis saulcyi (Guerin). 

 *Tafalisca lurida Walk. 



&H. 



The species preceded by an asterisk appear to be the only forms 

 which have not been accidentally introduced by man. Three of 

 these nine species are known only from the keys, five from the keys 

 and the jungle-like "hammock" land of the subtropical region of 

 Florida, and one from the latter only. This evidence shows that 

 half of the tropical species which have become permanently fixed 

 in this region were, in all probability, accidentally introduced by man, 



