Hurter — Herpetology of Missouri. 171 



When driven to bay, its tail will quiver with rage, making 

 quick vibrating motions, which, among dry leaves, will 

 produce sounds not unlike the whir of the Rattle Snake. 

 May 1, 1898, I caught a Blue Racer just swallowing a 

 Copper-head about two feet long. The victim had about 

 half disappeared when I took hold of the Black Snake. 

 Before I had time to get it into my bucket it had dis- 

 gorged the Copper-head, which recovered. It is astonish- 

 ing how quickly one of these snakes entangles its victim. 

 In the twinkle of an eye it has wrapped itself around the 

 coveted morsel. It makes two or three coils, then a 

 squeeze, and the victim is dead. The snake looks for the 

 head and begins to swallow it, releasing its coils as the 

 swallowing progresses. 



Dates of capture. — April 8, 15, 22, 27; May 1, 6; July 

 13; Oct. 3. 



59. Bascanion constrictor flaviventris Say. Yellow- 

 Bellied Racer. 



Bascanion flaviventris, Zamenis flaviventris var. B., Zamenis constrictor 

 flaviventris, Coluber flaviventris, Coluber constrictor flaviventris, 

 Coryphodon flaviventris, Coryplwdon constrictor vetustus, Bascan- 

 ium constrictor vetustum, Bascanion vetustus, Zamensis stejnegeri- 

 anas. 



Description. — Rostral large, about as high as wide, hollowed below 

 and bounded behind by internasal, anterior nasal, and first labial. A 

 pair each of internasals and prefrontals. Frontal long and narrow. A 

 pair of large parietals. Anterior and posterior nasal distinct, nostril in 

 the anterior one. Loral quadrangular. Preoculars normally two but 

 sometimes united. Postoculars two, upper one a little larger than 

 lower. Temporals 2-2, 2-3, or 1-2. Seven or eight upper labials, tbird 

 and fourth or fourth and fifth entering the eye, sixth and seventh 

 the largest. Eight or nine lower labials, four, in contact with the ante- 

 rior chin shield, are about equal. 



Head rather long, with flattened top, rounded snout. Dorsal scales 

 smooth, in seventeen rows. Ventrals 163-179. Anal divided. Subcau- 

 dals 79-98 pairs. 



Color. — The color above in adults is green, olive or reddish-brown, 

 changing to green on the lower rows of scales and on the tips of the 

 ventrals. Head and tail unicolor with the body. Beneath yellow, un- 

 spotted. 



