80MABRACHYS. By Dr. A. Seitz. 335 



19. Family : Megalopygidae. 



This curious family, which ranges over a great part ot tlie Globe, is throughout represented by very 

 pale forms, which are heavily clothed with hair and approach in facies partly the Limacodidae, partly the 

 Lasiocampidae. Most highly characteristic of this family is the presence in the larva of 14 instead of 10 pro- 

 logs, the 9th and 10th somites also being provided with abdominal suckers. 



These peculiar larvae are capable of withdrawing the head completely within the first segments; they 

 live free upon the food-plant, and some species are provided with extremely poisonous hair. To this family 

 belongs e. g. the South American larva called "Susuranna", whose yellow hair, if brought in contact with the 

 human skin, certainly produces the most violent irritation I ever observed. In Brazil I had occasion to treat 

 a woman who while picking fruit had accidentally touched a caterpillar of Megalopyge orsilorJms (Jr. On my 

 arrival the inflammation had already spread from the hand to the arm and seized the upper half of the body, 

 and it took a fortnight for the high fever to go down and to enable her to leave the bed ; moreover, I was told 

 by the Indians — who, however, are greatly given to exaggeration — ■ tha;t if such an inflammation affected 

 the mucous membranes of the head of children, not infrequently death resulted. 



In this extraordinarily violent action of the poisonous hair the Megalopygidae are rivalled by the Lima- 

 codidae, some species of which, as e. g. Nmern (Parasa) consocia from China or Sibine nesea from South America 

 are provided with stinging organs, and occasionally derive their names from those properties, viz., the Austral- 

 ian Doratifera vulnerans Lew. 



Also the metamorphosis of the Megalopygidae is most peculiar, and strongly recalls the Limacodidae. 

 After ha\ang spun their very regular, egg-shaped cocoon, in which the species provided with long wavy hair 

 very artfully make use of these locks, giving the cocoon the appearance of a curly wig, there commences a sort 

 of ante-pupal state ; and in like manner as the larvae of our northern species of Lirmicodes pass the winter 

 in a shrivelled, dormant condition and only form the pupa proper about 4 weeks before the development of 

 the imago, the North African genus Somubrachys passes the hot and arid summer peculiar to the southern part 

 of the Palearctic Region in the same state, changing into the real pupa only when towards the end of summer 

 the first rains approach. 



Another peculiarity is noticed in the manner in which the imago opens its artful prison. The North 

 American species Lagoa pyxidifera, "the boxmaker", opens its house so regularly and according to all the rules 

 of art, that the lid remains attached to a sort of hinge as in a beer-mug, and may be closed again at will, 

 in which case the cocoon appears quite intact. The same phenomenon was observed by Powell in the Palaearctic 

 Megalopygidae, in which peculiarity thej^ again resemble the Limacodidae. The other characteristics 

 of the only specifically Palearctic genus occurring within our region are given below. Here I only wish to 

 mention a curious orga,n first discovered by Jordan in the larvae of Somabrachys, consistmg of a rake-shaped 

 appendage attached to the anal extremity of the larva and provided with 4 teeth, which being ordinarily 

 hidden under the anal segment is used during the process of evacuation for removing the excrements. 



1. Genus: liouiabrachys Kirby. 



Comprising a number of rather small-sized, unicolorous forms; but the number of species is difficult 

 to determine. The ^^J, while externally resembling those of Chondrostega, are of wee.ker build, having occasionally 

 the abdomen atrophied. Antennae pectinate, frons covered with woolly hair, eyes hidden, the woolly thorax 

 heavier, legs delicate, abdomen very small. The forewing has the costa elongate, somewhat concave as in Chon- 

 drostega, apex produced but rounded, occasionally lobe-shaped, the inner margin straight ; the terminal border 

 presenting such a regular curve that the inner angle is represented by a perfectly regular arc. The course of 

 the subcostal diverges from the costal, rendering the cell very elongate, wedge-shaped; the upper and middle 

 discocellular run at a right angle to one another, the middle and lower ones at an obtuse angle ; the upper radial 

 is strongly curved. Hindwing oval, feebly angled at apex, terminal border uniformly rounded. Eggs elongate 

 egg-shajied, flattened at the poles; they are deposited in layers on twigs or blades of grass in such a manner 

 that they are arranged in longitudinal rows, the poles touching, the micropyle slightly elevated. Often one 

 finds a dozen or more of such rows side by side or on tojD of one another, thinnmg out in front and behind. 

 Larvae feed on herbaceous plants; they are not unlike those of Zygaenidae, from which they may be easily 

 told by the greater number of prolegs; they are thick, puffed-up, soft-skinned, provided with isolated, short, 

 soft hairs which produce an irritation upon the skin of sensitive persons. (Whereas I never personally suf- 



