130 NATURAL HISTORY SOCIETY OF DUBLIN. 



Penthophera. The limits of the genus have been extended by the dis- 

 covery of numerous Australian, Ceylon, and East Indian species, but it 

 has been broken up by some authors into several different smaller genera, 

 very unnecessarily, however, it seems to me. These extraordinary in- 

 sects present some remarkable peculiarities in their life history, as ob- 

 served by Saunders, Guilding, and Westwood, and in their affinities 

 they rank beside the Psychidae, or " Sacktragers " of the Germans. 

 These constitute a sub-division of the Heterocerous Lepidoptera. 



The first and best known individual of the series is the case of Oiketicus 

 Saundersii(0. elongatus, Saunders),* and my specimen is probably the ha- 

 bitation of the female insect, whose dwelling is always longer and wider 

 than that of the male. My specimen measures about seveninches in length, 

 is somewhat ovato-lanceolate in shape, wider towards the upper or oral 

 end, and being about two inches and a-half in circumference at its 

 widest part, tapering to a soft flocculent open extremity at its distal 

 end. The oral extremity is open, soft, and leathery, tearing with con- 

 siderable difficulty. The exterior is of a dark grey colour, but the in- 

 terior is of a light yellowish brown, very much resembling the hue of 

 chamois leather. On the exterior there are to be seen a large number 

 of small portions of twigs one inch in length, and all about the same 

 degree of thickness. These are arranged in a double spiral row, one 

 alternating with the other in such a manner as to give to these twigs 

 on each side a quincuncial appearance. They are sunk one-third of 

 their thickness into the wall of the structure, to which they are firmly 

 adherent, and separable with very great difficulty, the connection being 

 maintained by the adhesion of the woolly threads of the nest wall to 

 all the irregularities on the extremities and cortical layer of the sticks. 

 These surface twigs are not, except in rare cases, in contact with each 

 other, and they are all arranged parallel to the long axis of the nest. 

 Those immediately surrounding the inferior end are only attached to 

 the nest by one extremity, and hang loosely around the soft distal 

 extremity, being free for about three-fourths of their extent. The 

 material of the nest wall is tough, and cuts like felt, which in reality 

 it is. On the inner surface it very closely resembles chamois leather 

 or very fine flannel in appearance, and no traces of the external twigs 

 are visible on this aspect. Externally it was , covered with a soft 

 brownish or greyish nap or fur, which, however, is worn off in many 

 parts, and this rests on the grey, firmer basis of felt. Microscopically 

 this nest consists of delicate interlacing somewhat compressed or flat- 

 tened threads, not branching, but felted together to form a dense stratum, 

 and in this respect the tissue is similar on both surfaces of the wall. 

 These threads are an animal nitrogenised secretion ; they evolve an 

 odour when burning like the smell of burnt bones, and agree in chemical 

 nature with silk. Scattered on the outer walls are a number of rigid 

 black or brownish hairs, also probably animal in their nature. The 



"Trans., Entorn. Soc," 1847, vol. v., p. 43. 



