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hoods on its legs, by the greatly developed spur, and by the great length 

 of the proximal tarsal segment in comparison to the tibia. In the other 

 species the tibia is at least four times the length of the proximal tarsal 

 segment, while in this species it is only twice as long. 



See Plate I, figures 1, 2, and 3. 1, Megamelus ; 2, Leaf-hopper from 

 the Juncus area ; 3, Leaf-hopper from the area never covered by ordinary 

 tides. The species whose hind leg is figured in 2 retreated before the 

 tide, but on no occasion during the summer was the region it inhabited 

 completely submerged. These figures show a peculiar development of 

 structures of advantage in each particular environment. No. 3 has no 

 hoods, No. 2 has them somewhat developed, in No. 1 we find the greatest 

 development. If, as I have suggested, these hoods have been developed 

 to aid in hopping on the surface of water, No. 3 would have no use for 

 them and they would necessarily be useless structures. 



The chief enemy of the Megamelus marginatus, is the only other perma- 

 nent resident of the Spartina area, a small spider, Grammonata trivittata. 

 Its principal source of food is this leaf-hopper. 



The hoods on its feet, the greatly developed proximal tarsal segment, 

 and the spur, are the peculiar modifications which determined that this 

 leaf-hopper should inhabit this particular region. But why it is only 

 found in the Spartina region, is not as easily answered. It may have been 

 the severer competition in the other regions of the marsh, or perhaps the 

 Spartina grass is its favorite food, the one on which it is especially 

 adapted to live ; or, again, the habits necessary for its continued existence 

 in the tidal zone may make it the easy prey of its natural enemies living in 

 the other areas. 



I could not compare the resistivity of this leaf-hopper to drowning 

 with that of those farther back on the marsh, because I could not get 

 any of them to remain under water without placing them in vials covered 

 with cheesecloth. Two to four hours submergence usually killed them. 

 Even the leaf-hopper of the Spartina could only survive for several hours 

 when submerged in this manner. This may suggest that the leaf-hopper 

 may secure its air supply from the Spartina by piercing the blade to the 

 air channels. I have no experimental evidence to prove this. 



Gkammonata Trivittata. 

 This spider inhabits the salt marshes from Long Island to Maine 

 (Emerton). The females are about 3.5 mm. long. Their color is a dark 



