NYMPHALTS. 307 



Hind Wmgs large, somewhat ovate, not ocellated beneath. Costal margin arched. Outer maro-in more or less 

 dentate, and tailed; the tails being produced at the extremity of the first and third branches of the median 

 vein. Precostal vein oblique ; the tip rather suddenly bent outwards. Discoidal cell small and narrow ; 

 closed imperfectly by a very fine disco-cellular veinlet, which unites the discoidal vein with the median vein 

 just before its third branch is thrown oft". 



Fore Legs of the male very minute, scaly, and clothed with fine, silky, rather short black hairs above, and white 

 ones below ; the tibia and tarsus being together not, or but little, longer than the femur. The tibia twice 

 the length oi' the tarsus, which is indistinctly articulated beyond the middle and towards the tip, when 

 denuded of scales. Fore Legs of the female half as long again as those of the males, scaly. The fenuir with a 

 slight row of fine hairs on the inside. Tibia two thirds of the length of the femur. Tarsus about as loner as 

 the tibia, compi-essed, dilated at the tip, which is obliquely rounded off, with several pairs of spines towards 

 the tip on the under side, indicating the articulations; the basal joint being scarcely more than half the lenn-th 

 of the tarsus. 



Four Hind. Legs rather sliort, very robust, finely scaly. Tibia shorter than the femur, flat beneath. Intermediate 

 tibia with an oblong patch of delicate plush at the base ; each side with a row of fine short spines. Tibial 

 spurs short. Tarsi robust, scaly, with four rows of short spines beneath. Ungues moderate. Paronychia 

 very small ; the inner lobe very short ; outer lobe acute, curved. 

 Abdomen rather short ; nearly ovate in the female. 



Larva without any spines on the body, which is gradually attenuated behind; terminated by a depressed 



bicuspidated tail. The head armed with four obtuse horns. 

 Chrysalis abbreviated, rounded, subconical, scarcely carinated down the back. 



The present genus contiilns an extensive series of some of the finest species of t!ie present family ; the majority uf which are 

 distinguished by each of the hind wings being furnished with a pair of tails, by the elegant markings of the under surface of the wings, 

 and by the greatly elongated condition of the fourth branch of the postcostal vein of the fore wings, which arises at a sliort distance 

 beyond the discoidal cell, and which is curiously bent downwards towards the tip of the wings. 



The propriety of applying the generic name Nymjjhalis to this group will doubtless be questioned. That Linnreus, the first author 

 by whom the name was a|)plied, had no decided idea of tiie contents or characters of the group to which he applied the term is evident, 

 even to the tyro ; we should, therefore, as I apprehend, be at liberty to look for the types of the genus when It became more 

 satisfactorily established in the Encijclopedte Methodiqxie. Here it is evident that the present insects, occupying, as they do, the head of 

 the genus, were regarded as its types ; and as such I am inclined to consider them, notwithstanding the form uf tlie lai\:i, w Inch 

 approximates so closely to that of Apatura, that j\I. Boisduval has united these two genera into a tribe named Apaturldes, distinct 

 from the Nymphalides, of which he appears to regard Limenitis Populi as the type, giving to that insect the generic name of 

 Nymphalls. 



The following observations on the typical species, P. Jason Linn., are extracted from Wilson's Illustrations of Zoology (fol. 27.) : — 

 " This butterfly is one of the largest, rarest, and most beautiful of the European Diurnal Lepldoptera. Lefebvre de Cerlsy has paid 

 considerable attention to the metamorphoses of this fine Insect. The Caterpillar, which In its early stage Is green, becomes afterwards 

 of a yellowish hue, and its skin Is, as it were, shagreened and transversely plaited. Its head is singularly armed with four vertical 

 yellow horns, tipped with red, of which the two intermediate are the longest. A yellow line passes along eacli side of the lH)dy, in the 

 region of the stigmata, and the back is marked with four Indistinct orange spots. The true feet are black, the membranous ones green. 

 It feeds on the leaves of the strawberry tree, and never eats except during the night. Its habits are very lethargic. During daylight 

 it remains fixed and motionless on its favourite plant, wliich it I'esembles in colour, and thus escapes observation. The Chrysalis Is 

 smooth, thick, carinated, and of a coriaceous texture ; the colour, pale green. Two broods or flights of the Perfect Insect are produced 

 each year ; the first in June, the second in September. The caterpillars of the autumnal brood survive the winter, and are not 

 transformed into chrysalids till the ensuing May. The perfect insects are then produced in about fifteen days. These sjioedily deposit 

 their eggs, which are hatched in June ; and, after three months occupied in the usual transformations, the second flight appears in 

 September, and continues the race In the manner above mentioned. In many parts of France, this butterfly is named the ' Pacha 

 ■with two tails.' " The transformations of this species have also been carefully observed and described by Signor Costa, in the Favna del 

 Reyno di Napoli, and by INI. Dujjonchel ; the latter In his Iconograpliie des Chenilles, and in a " Notice sur les Particidarltes que 

 presentent les Changeraents de Peau de la Chenille da Charaxcs Jaslus," Inserted In the Annales de la Societe Entoniuhiijique de. 

 France (tom. vi. 1837). This peculiarity consists In the circumstance of the envelope of the head of the caterpillar. Instead of being 

 slit into three parts (as is the general custom with Lepidopteruus larva; on undergoing their moultlngs), being cast oft' entii'c without 

 any alteration either of form or colour, so as in fact to look like the head itself, a minute or two before it disengages itself from the skin 

 of the remainder of the body. This remarkable mode of shedding the covering of the head is efl'ected in the following manner. For 

 three days before moidting, the head, which was previously held in imrlzontal position, is gradually depressed in front, so as to 

 assume a vertical position, by which means the skin of the back of the neck is slit across; whereupon, by a swelling and retractile 

 movement of the three anterior segments of the body, the remainder of the head is withdrawn from its ancient covering. The new 

 skull is at least three times the size of the old one ; at first it Is rounded in front, but the horns are rapidly developed ; in fact, during 

 the few days preceding the moulting, four small tubercles are observed on the hind part of the first segment, containing the rudiments 

 of the four horns of the new skull. Hence, although apparently the new skull is formed from the first segment alone, independent of 

 the preceding head, M. Dnponchel supposes that it is owing to the increased size of the enclosed skull that it is forced backwards into 

 the first segment ; the cast head, being in fact hollow, presenting only the envelope of the different organs attached to it. Some 

 specimens of the larvfe, received by M. Dnponchel, in the middle of January, from Hyeres, underwent the change to the chrysalis state 

 between the middle and end of the following August, and the jjerfect insects were developed at the end of the following May and 

 beginning of June ; which proves that on some occasions, instead of there being two broods in the course of one year, as above stated, 

 it requires a year and three quarters or two years to bring the species to perfection. 



November 1. 1850. 4 M 



