( 565 ) 



Individually variable. The jiatch SC' — R' on tlie npperside of the forewing 

 is nsnally excised, seldom completely divided, the black siuns being often rednced 

 to a spot, which is sometimes altogether absent, as is always the case on the 

 underside. Some specimens have a complete row of submargiual spots. One of 

 the most interesting variations is represented by specimens in which there is a 

 second yellow spot before the subcostal fork standing at the proximal side of 

 the subapical spot, this additional spot proving the suba])ical spot to belong to the 

 submarginal series, not to the discal band. The size of the discal patches is very 

 variable, spots R' — M" being more or less pointed distally. There is apparently 



never a yellow spot in the cell, as is so often the case in P. thoas. The width of 



the yellow antemedian band of the hindwiug is variable. 



On the underside considerable variability obtains in the amount of black on 

 both wings and in the size and number of the orange spots on the hindwing ; these 

 spots are occasionally of a rufous tawny tint. 



There is apparently no marked variation according to season and locality. The 

 few Cuban males which we have examined show, however, a more or less distinct 

 orange-red spot in the cell of the hindwing below, which spot is hardly ever 

 indicated in continental specimens ; our Cuban females do not possess the spot. 



The specimens from the southern Atlantic States are on the whole the largest, 

 the Central American ones being, on the contrary, of inferior size. 



The distribution is somewhat fluctuating, the occurrence in the northern 

 districts of the range not being regular. We suspect the species to be a wanderer 

 also in the southern districts. 



P. cresphontes was originally doubtless a northern form of P. thoas. The 

 ranges now overlap to a considerable extent, the insects having become so difi'erent 

 that they are independent of one another and can exist in the same locality without 

 fusion (compare definition of " species " in Nov. Zool. 1896, p. 438, and 1903 

 Suppl. p. xli ; also Poulton, Pres. Address, Etit. Soc. Lond. 1903). 



Genitalia : S. Tenth tergite with a very short process instead of the long 

 spatulate process of P. thoas, there being in consequence an open space dorsally 

 between the claspers ; the process of cresphontes can be felt by gently moving 

 the finger over the upper edge of the claspers from behind ; the tenth sternite, 

 which in thoas bears on each side a long curved pointed process which is 

 proximally dilated into a hairy ridge, has in cresphontes a long proximal 

 process which is somewhat irregular at the edges, being narrowed to a point ; 

 from beneath this process, i.e. standing distally of it, projects an acute and 

 somewhat curved thornlike process. Clasper shorter and much more rounded than 

 in P. thoas ; harpe broad, hollowed out, narrowest at apex, which is rounded, 

 the apical and ventral edges being minutely denticulate, no apical process as in 



P. thoas. ?. Edge of vaginal orifice anteriorly raised into a small, smooth 



trtbercle, and posteriorly into a transverse ridge ; from this ridge extends on each 

 side backwards a longitudinal ridge bordering a large mesial depression ; just 

 in front of the orifice a fold which is laterally raised into a small triangular Libe. 

 Anal segment on inner surface with tliree bristles on each side. 



Early stages similar to those of P. thoas. 



Hah. Canada to Costa Rica ; Cuba. 



In the Tring Museum 66 $$, 54 ?9 and some larvae and pujiao from: 

 Buffalo; Evanston, and St. Augustine, Illinois (Snyder); Nashville, Tennessee 

 (W. Osburn); Iowa ; Jefferson Co., Kentucky (Troxler); Louisiana; Florida ; Cuba; 



