FROGS. 9 



The screens have to be placed far enough back from the lake shore to avoid water 

 rising too near the surface and thus destroy the traps. On the swampy ground the 

 holes are similarly obliterated by the water. To overcome this difficulty, Mr. A. W. 

 Thierre, of Lower South Bay, has devised a trap of woven wire screen; with a one- 

 half-inch mesh. If this trap was placed at an opening in the screen, which is not 

 the case, it would allow the undersized frogs to escape and to reach the lake and find 

 proper winter quarters, while the screens tend to destroy both the smaller kinds of 

 frogs and immature individuals of the larger species. This wire trap has an inclined 

 surface up which the frogs crawl, and from which they fall into the trap cavity, and 

 from which they seldom escape. Thierre also uses a large minnow box to store his 

 frogs until delivery to the dealers. » 



By means of the screens and traps a single night's catch may amount to about 500 

 pounds, from about a half mile of screen in a good locality. As much as $70 has been 

 paid for a single catch. 



In many regions, as in central New York and elsewhere, the pro- 

 fessionals come to know where the frogs hibernate and often dig 

 them out of the mud in large numbers. In the Erie Canal, after the 

 water is withdrawn, many frogs are taken from the mud or even 

 from beneath the ice of some of the pools. 



A favorite method of capture at night is to use a bull's-eye or any 

 form of bright light. The frogs are dazed and in most cases can be 

 caught by hand or approached near enough for their easy dispatch. 

 Sometimes in the deeper waters and swamps two men are needed for 

 this form of capture, one to row the boat and the other to locate and 

 shoot the prey. The lantern may be on the prow of the boat, carried 

 in the hand, or worn on the head, as with alligator hunters. The rifle 

 and spear and gig are used mainly in Illinois, Arkansas, Missouri, and 

 Tennessee. The sjaear may be one of several sorts,* three-pronged or 

 single, or merely a nail or a straightened fishhook in the end of a pole. 



COMMERCIAL FROGS. 

 DESIRABLE SPECIES (PLS. I, II, AND Hi). 



The six eastern edible species fall into two groups of three each: 



Those with more or less uniform dorsal coloration on the back, and 

 with an eardrum larger than the eye in the male, namely, the green 

 frog (Rana clamitans), the bullfrog (R. catesheiana) , and the southern 

 bullfrog (R. grylio). 



Those which are blotched or spotted on the back and with the ear 

 of the male not larger than the eye, namely, the leopard frog {Rana 

 pijnens), the southern leopard frog (R. sphenoc&phala) , and the pick- 

 erel frog (R. 'palustris). 



In the western States three species enter into commercial catches. 

 They are the yellow-legged frog (Rana boylii); the western frog (R., 

 pretiosa) ; and the "western bullfrog" (R. aurora). 



The above nine forms are all true frogs (Rana) which have teeth 

 on the upper jaw, no adhesive, enlarged disks on the ends of the fin- 

 gei-s and toes, and no large parotoid gland back of each eye. Most 

 of them are smooth of skin, and all reach an adult length of at least 

 3 inches, not comiting the hind legs. 



EASTERN SPECIES. 



Green Frog. — The green frog (PL II, fig. 1) is larger than a leop- 

 ard frog and has two ridges down its back. The forward upper parts 

 are bright green; the posterior region, brown or olive. The under 



