SCOKPIONS AND DRAGON-FLIES 179 



according to Prof. Kolbe,* on account of its feeble development 

 and weak flight. Taking into consideration the general dis- 

 tribution of ^this genus, he favours the view of a former 

 ancient land connection between the Antilles and North 

 America. 



In its butterflies and moths Florida is united to Central 

 America and the Antilles, and it is from the latter that such 

 genera as Heliconius, Dione and Agraulis gained a foothold in 

 the northern continent.f 



An exceedingly ancient group are the woodlice (Isopoda) or 

 " sowbugs " as they are sometimes called in America. In 

 eastern Europe at Odessa, and again in north-western Africa, 

 an interesting very peculiar species occurs which is known 

 as Tylos latreilli. The same species has been, met with in 

 southern Florida and in the Bermuda islands. A case of that 

 kind is generally set down at once as an instance of human 

 importation. The possibility of the survival of such a species 

 through several geological ages is not even discussed. But 

 in southern Florida a second species of Tylos has been dis- 

 covered which occurs elsewhere only in Bermuda. This 

 species, known as Tylos niveus, is white in colour and pos- 

 sesses structural differences distinguishing it from the other. 

 Of the genus Cubaris, which is widely distributed through the 

 Antilles sand westward to Mexico and California, a single 

 species (Cubaris pisum) occurs in Florida, and is peculiar 

 to it.f 



All these, it may bp objected to, are inconspicuous creatures 

 that might have been overlooked elsewhere. Too much im- 

 portance, it might be urged, should not be placed on their 

 occurrence in Florida. We may return, therefore, to more 

 conspicuous objects. 



Everyone in America knows, or has heard of, the alli- 

 gator (Alligator mississippiensis), though it is only found 

 in the southern states of North America. Its distribu- 

 tion in fact is rather limited. From Florida it extends 

 northward to Carolina and westward as far as tlie Eio 



* Kolbe, H. J., " Neuroptera der Antillen," pp. 157158. 



t Pagenstecher, A., " Verbreitung der Schmetterlinge," p. 359. 



\ Eichardson, H., " Isopods of North America." 



N2 



