486 Mr. H. Pryer on certain temperature 



at the same level, are very severe. We frequently have 

 10° to 12° of frost in the winter, and in summer the 

 thermometer is frequently 88° to 90° Fah. in the shade, 

 and the sun is then very powerful. 



Papilio Xuthus and Xuthulus. — This insect is generally 

 found feeding on the Karatachi {Citrus trifoliata), and 

 Inusanchiyo {Xanthoxylon schinnefolium) ; it is very 

 abundant, and a succession of broods appear during the 

 year ; the insect first appears as an imago in March 

 (the larva having fed up in the colder period of the 

 autumn) ; it is then the form known as Xuthulus : another 

 brood begins to appear in June, and is intermediate 

 in size and coloration between Xuthulus and Xuthus. This 

 form has a dimorphic female, which is sometimes yellow 

 and sometimes pale-coloured. The early Xutlndus form 

 has a red spot at the anal angle of the hind wing which 

 is quite lost in the summer broods, which are much 

 larger and darker. I have specimens of the small tem- 

 perature form Xuthulus under three inches in expanse, and 

 of the large Xuthus over five inches. I took the XutJiulus 

 form on the Ogasawara Islands (Bonins), 500 miles due 

 south of Yokohama, in March, although the temperature 

 there then was as warm as in June at Yokohama, proving 

 that the cold during the time the insect had been in the 

 larval stage had been sufficient to produce this form 

 instead of the large dark Xuthus form. This species is 

 abundant everywhere. 



Papilio Machaon. — This insect feeds on the cultivated 

 carrot, fennel, and other plants. The difference between 

 the temperature forms is very striking ; March specimens 

 are about 2i to 2| in. in expanse and very pale-coloured, 

 the summer forms expanding over five inches, and are 

 very dark handsome insects. No alteration takes place 

 in the markings, the colours being intensified only. It is 

 very abundant everywhere. 



Papilio Alcinous. — Feeds on a climbing-plant, I think 

 a species of Asclepiadece. The larva and pupa are very 

 extraordinary ; the first, when full-fed, has the appear- 

 ance of a large mulberry, and the pupa looks more like a 

 mollusc than the pupa of a lepidopterous insect. The 

 imago first appears in April, and is generall}^ then smaller 

 than those appearing later on. This insect being almost 

 unicolorous, cannot otherwise alter, except in size. I 

 have noticed that the early spring male has rather an 

 unpleasant sour smell, whereas the summer specimens 



