CATALOGUE OF PAL^ ARCTIC URBICOLIDES. 195 



negatives should be employed with the object in view of their 

 suitability for making lantern slides therefrom. The process, 'par 

 excellence,' is the dry collodion process, and I have used a home- 

 made collodion emulsion for many years. Plates prepared by this 

 process have a structureless film, and give perfect detail, with a wide 

 range of gradation in the image from clear glass to pure blacks. They 

 have also the merit of cheapness, rapidity of preparation and drying, 

 with permanency of the resulting slide. In most cases, the ordinary 

 method of preparation of objects will be satisfactory, i.e., treatment 

 with liquor potassa, dehydration with alcohol, clearing with oil of 

 cloves or turpentine, and mounting in Canada balsam. A good formula 

 for the latter is — Canada balsam (dried), 2 parts ; benzole and turpen- 

 tine, of each 1 part. For some objects, however, Canada balsam is 

 unsuitable, such as the softer and more colourless insect structures. 

 For these, glycerine, in the form of Farrant's medium, will answer best ; 

 for others, such as some scales and wings of lepidoptera, the dry 

 method of mounting is more suitable. 



It is desirable to keep an indexed record of the subjects photo- 

 graphed, giving such particulars as — name of specimen, generic and 

 specific, whether male or female, where obtained, how prepared, 

 objective used, amount of magnification in diameters, exposure and 

 date, and other facts that require notice. Such a record is always 

 valuable for reference. 



Explanation of Plates viii and ix : Notolophus (Orgyia) antiqua. 



Cocoons, § size. 



Pupse, male and female, 



I size. 

 Rudimentary wings of female, 



x8. 

 Hairs on larva x 10. 



,, ,, ,, x60. 

 Proleg of larva x 32. 



Note. — Figs. 1, 2, 3, 6, 7, and 8 have been photographed with a wide angle 

 photogrephic lens. Fig. 4 by reflected light. Figs. 5, 9, 10, 11, and 12 are 

 examples of low power photomicrography. 



Catalogue of the Palaearctic Urbicolides. 



By J. W. TUTT, F.E.S. 

 Our study of the Palaearctic "skippers " [A Xatiiral History of the 

 British Butterflies, pp. 80-298) has carried us over a considerable 

 amount of ground, and, in conclusion, we have drawn up the following 

 catalogue of the species that are taken within the Palfearctic area, Avith 

 the addition of some few varieties of the species that we have specially 

 studied, that spread into the Nearctic region. It will be observed that 

 there are many additions to those in Staudinger and Eebel's Catalog, 

 3rd ed., 1901, but even so, we are not sure that the list is quite as 

 couiplete as it should be, for, although we have cut out the species 

 that inhabit western China up to the borders of Thibet, without 

 passing the boundaries of the latter, the general resemblance of some 

 of these species to other outlying Pal8?arctic forms, makes us doubt 

 whether such should not be rightly included in our list. On the 

 whole, however, we have decided to exclude these, and believe the 

 following wall be found a fairly accurate list of the " skippers " 

 inhabitino- the Palfearctic resion : — 



