13 1 8 BULLETIN OF THE BUREAU OF FISHERIES. 



peculiarities of structure (pi. cxxvii), or certain kinds of accessory material, 

 such as sharks' and skates' eggs, for example, may add to the value of the 

 exhibit. 



A rare and interesting form like the goblin shark (Mitsukurina owstoni) 

 might be shown, especially if placed beside a model of the living fish; but on 

 the whole alcoholic specimens decidedly detract from the interest of the exhibit. 



(2) Mounted and painted skins are sometimes effective for exhibit, espe- 

 cially with fish like the gar-pike {Lepisosteus osseus), the enameled scales of 

 which are very successfully treated in this way. (PI. cxxviii.) In fact, this 

 method may be used with many forms that have close-set, substantial scales 

 (see yellow perch, pi. cxxix), and is especially effective in a fish of either gaudy 

 or dark colors (e. g., the angel-fish, or the groupers). It does not, however, 

 efi'ectually reproduce the smooth, gleaming, iridescent body of other fishes, as 

 the shrinkage and hardening of the drying skin and the paint that is applied 

 obscure the original quality of the surface. Hence, painting a skin practically 

 amounts to nothing more than painting on an inferior surface. 



(3) Casts, however, though but a reproduction, are faithful, if well executed, 

 and furnish a surface much better adapted for coloring. Transparent colors 

 over a metallic silver paint may be made to give the effects of iridescence, 

 especially with such fish as the mackerels, pompanos, and the lookdown. But 

 even the plaster cast, no matter how well painted, nevertheless does not 

 perfectly succeed in giving the surface bloom of the living fish. 



(4) Models. — Some fishes, especially the rarer forms, are hard to procure 

 except as distorted alcoholic specimens, yet it may be desirable to represent 

 them in the exhibit. In such cases, if sufficient data can be procured, a model 

 may be constructed giving a restoration of the original and it may be well to 

 exhibit the alcoholic specimen beside the model. 



(5) Skeletons. — The exhibit may be varied and its value greatly increased 

 by the use of mounted skeletons of typical forms. These may be correlated by 

 appropriate labeling so as to bring out their chief differences. 



(6) Colored plates taken from published works will add to the attractiveness 

 of the exhibit and may be used to represent rare species which could not other- 

 wise be shown. Many of these plates possess artistic beauty and represent the 

 living fish better than any known method of artificial preparation. At the same 

 time they portray the extraordinary variety of color and form possessed by the 

 fishes of tropical seas. Some of these plates are shown in plate cxxx. 



(7) Groups. — It is the pictorial group, however, that calls forth the greatest 

 display of interest on the part of the visitor. Groups are the attractive feature, 

 the drawing card of an exhibit. In bird and mammal collections they have 

 been employed with great success. There are, however, comparatively few 

 fish groups, and in these the mistake is often made of producing an aquarium 



