PAPILIO XIL, XIII. 



alcohol, but fifteen were allowed to go to pupation. The first chrysalis formed 

 5th July and this gave butterfly 25th July, or at nineteen days. The second 

 formed 8th July and the butterfly came out 28th, or at twenty days; both 

 female. On 25th August came a male at seventeen days, on 28th a female at 

 nineteen ; and others appeared at intervals to 5th September. Later some chrys- 

 alids which I supposed were hibernating gave butterflies irregularly, the last on 

 18th November. One large male came 26tli April, and two chrysalids died dur- 

 ing the winter. This male was fully as large as any of the fall brood and in ap- 

 pearance like those. 



The larva of Rtitulus is in habits similar to Turmis. It is sluggish, scarcely 

 moving at all. It weaves a web across part of the upper surface of the leaf it 

 rests on, whereby the leaf is somewhat drawn together, enough to leave an open 

 space between the web and leaf. The web serves as a bridge on which the larva 

 lies in comfort when a flood pours down the leaf. I measured one of these webs 

 on which a full-grown Turnus rested, and found it two and a half by one and a 

 half inches in extent, and four tenths inch above the bend of the leaf. It was so 

 firm that I observed no depression from the weight of the larva. On sprinkling 

 water vertically upon the leaf, it passed through the web readily. 



I fed both weeping and golden willow, and they were equally relished. Al- 

 though Turnus is known to feed on many species of plants, and of widely different 

 groups, no one has observed willow to be one of them, and when I have at- 

 tempted to force the larviie to eat willow, it was without effect. In California 

 are many plants allied to those on which Turnus feeds, and that RutuJus should 

 be nearly restricted to willow shows a difference quite as significant as anything 

 seen in tlie larva or imago. During part of the summer I was rearing a lot of 

 Turnus larvae from the egg, and so was able to compare the two species stage by 

 stage, with the results before set forth and shown on the Plate. 



Note. AVhile this paper was passing through the press, Mr. James Behrens wrote me from Mt. 

 Shasta, Cul., that he had recently found larvic of Rutulus on a species of balsam-poplar, and fed them 

 with the leaves of this tree in confinement. 



