[67] FISHERIES OF THE UNITED STATES. 579 



which works a thumb-screw passing into a screw hole in the top of the 

 tank. A rubber washer fits under the rim of the cover. This style of 

 cover is more easily opened and closed than the former, and in the tanks 

 which have been supplied with it the mouth is made as large as the top 

 of the tank will permit. 



Glass Jars with Screw Covers, for the storage and transportation of speci- 

 mens. Made under Mason's patent. 



United States Fish Commission. 



These jars are of two styles and three sizes, pint, one quart, and two 

 quarts. Those with the smaller mouths are intended for holding pre- 

 served fruits, and those with the broad mouths for butter. By means 

 of the rubber washer, which fits between two surfaces of glass, these 

 jars can be hermetically sealed. They are the most reliable jars for the 

 storage and transportation of zoological specimens, under a certain size, 

 which the Fish Commission has yet made use of. 



Cork-stoppered Bottles of clear glass, for the storage and transportation 

 of small specimens. Made by the Dorflinger Glass Company, White 

 Mills, Pennsylvania. 



United States Fish Commission. 



These bottles are made for the Fish Commission of seven sizes, rang- 

 ing in capacity from one ounce to one pint. 



Homeopathic Vials, set of four sizes, contained 'in a storage tray. 

 Made by Whitall, Tatum & Company, Philadelphia. 



United States Fish Commission. 



These vials are made especially for natural history purposes, of heavy 

 tubing, in five sizes, from 1 drachm to 8 drachms. The mouths are 

 carefully rounded, and of uniform diameter in each size. Eubber stop- 

 ples are employed, and prevent any perceptible evaporation of alcohol. 

 The tray accompanying the vials illustrates the method adopted by the 

 United States Fish Commission for storing vials for convenience of ref- 

 erence. 



Glass Exhibition Jars, for the display of alcoholic specimens of aquatic 

 animals. Made by the Dorflinger Glass Company, White Mills, 

 Pennsylvania. 



United States National Museum. 



These jars are made of fifty-six sizes, and in several series, to suit the 

 different classes of objects. They are of clear glass, and are made extra 

 thick, to lessen, as much as possible, the danger of breakage ; the stop- 

 pers are carefully ground. The smallest jar of the series is 2£ inches 

 high by 2 inches broad, and the largest 24 inches high by 10 inches 

 broad. Many of the sizes are exhibited in the collections of fish and 

 aquatic invertebrates. 



