134 NATURAL HISTORY SOCIETY OF DUBLIN. 



The sixth individual (Fig. 3) is one of very great beauty and interest. 

 In shape it is long, slightly tapering, cylindrical, open at the narrow end, 

 closed and fastened to branches by its thickest extremity. It consists 

 of four or five storeys of short, regular, and 

 very fine rods, like small grass stems. The 

 whole structure is about an inch and an 

 eighth in length. The first storey is about 

 three lines and a half long ; the second 

 very nearly three lines in length ; third 

 about two and a-half ; the fourth and fifth 

 are each about two in length. Each of these 

 are even, and the sizes of the component 

 twigs gradually diminish to the topmost 

 point. In the first part of the column, barely 

 a line and a-half in diameter, there are from 

 ten to sometimes twelve of these ; in the 

 second there are sixteen to eighteen, much 

 finer; in the third about twelve, still 

 smaller ; the fourth and fifth vary in the 

 number of their mural rods, but they are 

 generally about ten in the fourth and eight in the fifth ; the last 

 storey, however, is not always present. These branches forming the 

 wall have a slight twist, so that the two ends are not quite on 

 the same plane, but are placed obliquely, after the plan of the cham- 

 bering of an Armstrong gun. Each storey joins its neighbour very 

 nearly at the one level, giving a remarkably regular appearance to the 

 whole. The interior is smooth, firm, fine, and slightly silky ; the ad- 

 hesion of the twigs is by means of a felted material like the preceding. 

 I have not succeeded in identifying this remarkable dwelling with the 

 construction of any known " Sacktrager." Its closest ally would seem 

 to be the Ceylon species 0. Crameri ; but this is much shorter, and only 

 presents three fasces — one central long bundle and two terminal shorter. 

 This, perhaps, may be the representative of the habitation of a new 

 species, which, upon the principle adopted by Mr. "Westwood, provi- 

 sionally might be named after its discoverer, Mr. Hugh Macalister, an 

 accurate and skilful observer, as OiTcetius Macalisteri. 



From the cases themselves some assistance might be derived in the 

 classification of this group. There are two natural divisions into 

 which they might be arranged — first, those perforated at both ends ; 

 and, secondly, those with but one pervious end. Of the first group 

 we have — First, those with the twigs adherent for their whole length, 

 including 0. Saundersii and 0. Lewinii, distinguished from each other 

 by the first having sticks disposed spirally and separate, and the second 

 having but one row extending for the whole length of the sac, and 

 being nearly closed at one end. Secondly, those with twigs pendulous, 

 attached by but one extremity, as 0. Hubneri. Of those in which the 

 perforation is but at one end we have three forms — first not ornamented 

 with twigs, as 0, Herrichii; secondly, with irregularly disposed twigs, 



