1916.] NATURAL SCIENCES OF PHILADELPHIA. 283 



The specimens from Georgia, in addition to three from the same 

 locality previously recorded by us, 141 constitute the only record of 

 this species from the United States outside of extreme southern 

 Florida. 



Tridactylus apicalis Say. 



1862. T[ridactylus] terminally Scudder, Bost. Jour. Nat. Hist., VII, p. 425. 

 [Cambridge, Massachusetts; Maryland; southern Illinois.] 



District of Columbia. Georgia. 



Washington. IX. 1NN3, 1 o\ [Hebard Bainbridgc, IX, 17 to X, 19, 1910, 



Cln.l. (J. C. Bradley), 1 cr. 



Rock Creek, 1 9, [U. S. N. M.]. Spring Creek, Decatur County, V. 7 



T/ . . ■ to 23, 1911, 19,3 juv.; VII, 16 to 



ygima. 29, 1912, 74 <?, 319, 5 juv.; VIII, 



Stafford ( ounty opposite Fredericks- 26 to 28, 1913, Id", 19, (all J. C. 



burg, \ II, 20, 1913, (R. & H. ; wetsand Bradley). 

 near Rappahannock River), 3 juv. 



We are convinced, after study of the literature and all of the 

 material in our collections, that tertninalis of Scudder is an absolute 

 synonym of the present species, based solely upon large specimens 

 of pale coloration. We are also satisfied that Scudder has correctly 

 synonymized under these two names the following: tibialis Guerin, 

 1844; Xya mixta Haldemann, 1853; iUinoiensis Thomas, 1863; 

 fissipes Saussure, 1874, and incertus Saussure, 1896. The great 

 variation in the form of the cephalic limbs in the males of the species 

 discussed by Morse has in part caused this multiplicity of synonyms. 



The large series of males before us from Spring Creek, Georgia, 

 shows the same variability of the cephalic tibiae which Morse has re- 

 marked, and we find every gradation between the extremes; roughly 

 grouped, sixteen have the tibiae of the normal ( 9 ) form, eight have 

 them very slightly cleft; sixteen have them decidedly and thirty-five 

 very strongly bifurcate. A further interesting feature is apparent in 

 this series, for with scarcely an exception the specimens having these 

 tibiae least specialized are the smallest (averaging in length 7 mm.), 

 and throughout the series a distinct size increase accompanies the 

 greater specialization of the tibiae to its maximum development 

 (these specimens averaging in length 9 mm.). 



When compared with the males, the females of this series are found 

 to average noticeably paler in general coloration. 



The material before us shows that the wings normally reach a 

 little beyond the apex of the abdomen; occasional series have the 

 wings falling slightly short of this point. 



"JProc. Acad. Xat. Sci. Phila., 1912, p. 272, (1912). 



