I'lKiUNAK: TiiK (;kni:s KL'KYMUS. 1099 



tlif siilcs of tho wiiiu lire oblimioly coiupfessi'il, the lower, vonlriil, swollen pui'l l)eiiig 

 tninsversoly well rouiuled, while tlie Held of the otlier iippoiula^es is ilopi'essed ; thorax 

 somewhat elevateil, theiiicsothorax ridded with a. gentle arch, the sides inclined toward 

 each other at scarcely less than a risht angle, scarcely swollen, the ridjic transversely 

 ronnded ; the whole abdomen very broadly, gently and regnlarly arched; the whole 

 side of the body ridged, conimeucing with the frontal tubercle, passing through the 

 basal wing tubercle and the upper margin of the wing and continuing over the whole 

 of the fourth and succeeding abilominal segments just above the spiracles, to the sides 

 of the cremaster; it is Indistinct lu front of the wing tubercle, prominent and trans- 

 versely forming a right angle on the wings, conspicuous but not greatly elevated on 

 tho abdomen ; basal wing tubercle pretty large and rounded but not greatly elevated. 

 I'reanal button scarcely raised above the surface and distinct oidy by the apical tuber- 

 cles which are small, approximate, recumbent, anteriorly directed, swollen at base, 

 beyond conical. Cremaster viewed from above tapering consideralily, abruptly 

 docked, a little longer than its medium breadtii, transversely rounded, with a pair of 

 prominent, strongly compressed, rugulose, equal, parallel ridges, midway between the 

 middle and the sides, extending over the apical two-thirds of the cremaster. Viewed 

 laterally it is slender, tapers a little, is bluntly pointed, curves slightly downward and 

 has the margins raised ; the apical tlekl of booklets is transverse, broadest beneath 

 but not greatly broader than long. Ilooklets moderately long, the stem very slender, 

 a little curved, the apical portion bent suddenly over into a nearly circular domed 

 expansion, its general direction at right angles to the stem, the apex produced down- 

 ward and angulated. 



Tliis genus is the only one of the tribe which has its metropolis north of 

 the tropics, ami tlic (^pecics are alioiit etpially distriljuted between tlie Old 

 and New Worlds. In Africa and South America it reappears south of the 

 tropics and is even occasionally found within the tropics themselves, but prob- 

 ably only in elevated regions.* It extends to the high latitudes of the Old 

 ^^'orld as well as to Greenland and tlie land lying within the arctic circle 

 in America as far north as butterfly life exists ; some of the most northern 

 species are said to be common to both continents. It is not represented in 

 Australia, though a single species occiu's in some of the Pacific Islands. 

 In the eastern part of America, south of the colder regions, there are but 

 two common species, one of which is abundant only in the Mississippi 

 valley and westward, the other in the northern Mississippi valley and east- 

 ward. The latter is the commonest butterfly of Xew England and is 

 found througliout its limits ; tlie former has occurred there in a few instances ; 

 a tliird species belonging to Canada has once or twice been found in 

 northern Xew England. 



The butterflies are of medium size for Pierinae, varying from one and 

 one-half to two and a half inches in expanse. They are usually sidphur 

 yellow above but vary from soiled white to deep greenish orange ; both 

 sexes of the northei-n and alpine butterflies and often the females of the 

 temperate species are pale ; the outer border of the upper surface is bor- 

 dered with deep brown, often, especially in the female, enclosing pale 



Eurymus "in tropical America is confined the southern temperate zone ; no trace what- 

 to the highest platcau.x of Columbia, reappear- ever of the genus being found in the Amazon 

 ingin several specific forms in the plains of valley" (Bates, Journ. of entoui., 1S61, 230). 



