lower side, base of the tibiae, and under side of abdomen thickly 

 clothed with bright golden yellow hairs. There are also a few 

 scales of the same color at the base of the costa of the primaries 

 and along the sides of the abdominal segments. Antennae and 

 tarsi jet black, the latter with some yellow hairs at their base. 



Upper side: Ground color sordid white, as in P. Clarius 

 Evers., and P. Delphius Evers. 



Primaries with the posterior margins broadly smoky and 

 slightly transparent. Above the margin is a row of equal lunate 

 white marks, then a moderately broad blackish band, narrowing 

 a little at the interior margin, then a whitish maculate band, 

 broadest on the internal margin and reduced to a spot on the 

 costa. Anterior to this is a sinuate row of white spots, six in 

 number, not reaching the internal margin, which is whitish at 

 the base, dotted with black atoms, as is also the costa. Base of 

 the wing blackish, the cell with one large ovate, and one oblong 

 white spot. The system of markings of the primaries recalls that 

 of the genus Thais, and is different from any other Parnassius 

 known to me. 



Secondaries : Base and anal margin broadly black, the mark- 

 ings being very clearly cut around the upper portion of the cell, 

 leaving a well-defined ovate white space. From the anal angle 

 up to the second sub-costal nervure runs a wide black band, en- 

 closing at the anal angle one small round and one lunate red 

 spot. Between the second sub-costal and the discoidal nervures 

 is an almost conical red patch, and below it a small round spot, 

 also red. On the centre of the costa is a triangular red spot, sur- 

 rounded with black. The submarginal lunulesare very sharp and 

 distinct, as indeed are all the markings, and the fringes of both 

 wings are deep, intense black. 



Under side : Resembling the upper, but the markings are a lit- 

 tle fainter, and the wings have the glassy appearance so often 

 found on the genus. The secondaries have four red spots at the 

 base — the one on the costa small and almost linear, the second 

 nearly square, the third triangular, and the fourth oblong. The 

 other red spots have their centres white. 



Expanse of wings, 2. lo inch. 



Type. Coll. Hy. Edwards. 



This exquisite and very interesting insect was taken about 

 800 miles up the Yukon river, Alaska, by Mr. F. W. Smith, of 

 San Francisco, and by him kindly added to my collection. In 

 some respects it approaches closely to P. Eversmanni Men., but 

 differs from the figure of that species given by Mr. W. H. Edwards, 

 in the Butterflies of North America, not only in the color, which 

 is remarkably distinct, but in the broader black base of the pri- 

 maries, the wider bands, and the much larger proportion of black 



