30g NOVITATES ZOOLOOIOAE XXVI. 101 !•. 



the tip, light and broad at the base, and on segments 3, 4, and 5 there are small 

 pink side tubercles. Faint oblique lines mark the sides, the skin-folds below 

 the spiracles are pale pink and the ventral surface black. The pupa in form 

 appears to be identical with belus, but is always of a light lemon-green colour. 



A butterfly which emerged in the breeding-cage at 12 noon on June 23rd 

 1914, grew to its full expanse of wing in six minutes. 



P. crassus (pi. iii. fig. 11). 



For long this species was a puzzle to me, the butterfly being taken or seen 

 in all the open parts of the matto about Para with sufficient frequency to justify 

 the term " common," but never till 1917 could I trace the larva. At last it 

 turned up in a big gregarious batch of some 30 to 40 glossy black caterpillars, 

 exactly like helus, feeding on Aristolochia didyma, one of my new species, which 

 occurs in no great abundance here, but for which crassus appears to show a 

 partiaUty, as I have again found a number on the same plant. 



Since then I have also succeeded in rearing a large brood from the ova 

 of a captured female, which kindly consented to lay me about 80 eggs when 

 sleeved out on a growing plant of ^. didyma in my garden. As regards the larva, 

 there is no apparent difference between it and helus up to the day when the 

 colour changes prior to pupation ; crassus then, in lieu of the rich cadmium belts 

 of belus, assuming a pleasing steel-grej' colour touched up with small patches 

 of vermilion. 



The pupa also in form appears to be identical with that of belus, and is 

 only a degree Ughter in general tone. 



The species is once more a sun-lover, and in nature is probably often cradled 

 above one's head in the tree-tops. 



From its habits as well as its appearance throughout early stages it so 

 closely repeats belus that, numerically regarded, it is surely misplaced, lycidas 

 interrupting the natural sequence. There may be considerations of a more 

 fundamental nature anatomically, upon which I cannot pronounce, but at least 

 there are no such connecting links in the early stages of lycidas as those wliich 

 are so clearly seen to obtain between crassus and belus. 



As regards the butterfly, the extent and precise tone of the yellow scales 

 which adorn the forewing of the male — the female being constant — make crassus 

 a more varied, if less handsome, species than either of the others. 



We come next in order to the Fluted Papilios, which in the Para district 

 are represented by 3 groups and 6 species : thoas, aridrogeus, hyppason, anchisiades, 

 isodorus, and torquatus. 



DIVISION II.— FLUTED PAPILIOS. 



Thoas Group. 



P. thoas thoas (pi. ii. fig. 9, pi. iv. fig. 3). 



Always a common species in Para, the butterflj' frequenting the city gardens 

 more than the matto, and the larvae and pupae being readily obtained by 

 searching the small orange and lemon trees which abound in the vicinity. Food- 

 plants : Citrus, e.g. locally both sweet and bitter orange, tangerine, lime, lima. 



