^°i'8ai!''J i'Uoci:i:i)L\(;s of the national mi;.si:i;m. (i-43 



genus Lystrophis Cope* is found iu subtroi)icul and tenipenite Sctuth 

 America, which only dillers from Heterodoii in i>osse.ssiiii; smooth 

 scales. A genus occurs in Madagascar which agrees with Lystroiihis, 

 but (lifters in having an entire anal shield {Liohctcrodon Dum. Ilihr.). 



Tiie species of Heterodon have some ])ecnliar habits which iiidicato 

 greater intelligence than most other sn'akes possess. Thry tlirow 

 themselves into remarkable contortions when alarmed, and e.\i»and 

 their anterior ribs, inllate their lung, and open the mouth widely. 

 They do not attem[)t to bite from the ground, but the long ]»osterior 

 maxillary tooth may be used with considerable effect if the snake is 

 carelessly handled. The trowel-shaped rostral i)late enables them l<> 

 excavate sand with ease, and in such soil they arc usually most alum- 

 dan t. 



I. No accessory scales about the azy^os plate. 



Scales iu twcnty-fiYC rows ; rostral plate less developed ; larjjer . . . IJ. itlatijihinHH. 

 II. Accessory scales about the asygos scute. 



Scales in twenty-live rows ; stouter, smaller; an inferior nasal plate; one row of 



lateral spots ; belly white iu adults II. viinns. 



Scales in twenty-three rows; smaller, more slender ; no interior nasal seule ; two 

 rows of lateral spots ; belly more or less black H. nasivns. 



The H. plat i/rliinns ranges throughout the Eastern and Austroriparian 

 regions, and the JI. fiiinus inhabits the Austrorparian only. The 

 H. nasicufi is divided into two subspecies, one of which extends over 

 the Central and the other over the Sonoriau regions. 



Heterodon platyrhiuus Latreille. 



Reptiles. IV, IHOO, p. :V2, Figs. I, 2, :{ ; llolbrook, X. Amer. Herp.. ii, L-Jd. p. 117, I'l. xxi ; 



second ed., IV, 184-2, p. 67, I'l. XVii ; Dum. Bil)r. Kr|). lien., \ii, is.'.l, p. Tr.6; 



:}d. and Gird., Catal. Serj). N. Am., 1*'):?, p. 51 ; Cope, Check List LJatr. Hejit. N. 



Amer., 187.5, p. 43 ; Jan, Icou. Gen. Olid., in, 4S ill Fi;;. 2. 

 Col iihn- hctrodon Diindin. Hist. Nat. Kept., vii, 17'.Ht, p. 15:1, IM. (i ', Fi;; -'s ; 8;:y, Am., 



•lourn. Sci. Arts, I, 1818, p. 21)1 ; Harlan, Journ. Acad. IMiil.i.. 1SJ7. p. :r)7. 

 Coluber cacodtvnwn Shaw, Gen. Zool., in, 1802, \\. 377, I'l. 102. 

 Sci/talc ui<ier Daudin, Hi-st. Nat. Kept., \-. 1S03, p. 342 ; Harlan. .I..niii. .Vr.i.l. I'lnla., 



1SJ7, V, p. 31)7. 

 /'</i<(.s Hi(/(/- Merrem, 'reutanifii. ISJ", \<. II'.". 

 Ildirodoti ?ijf/ei- T roost, Am. Lye. Nat. Hist. X. York, iii, \>. iHi ; Holbrook. N. Amer. 



H«'n>.,iv, 1S42, p. (iO, PI. XVI ; Hd. and <;ird.. Cat. Serp. N. Anirr.. 1S.\!, ji. .55: 



l)uni. et Mibr., Krp. Gen.,vii, p. 7(>'.). 

 Ilrterodon cognatns Md. and (iird.. Cat. Serpt. N. .Vmer., 18.53, p. 51. 

 Heterodon atmodes 15d. and Gird., 1. v.. p. 57. 



Eastern region excei)ting Iludsoniandistrict ; Austroriparian region. 



Heterodon siinus Linn. 



Holbrook, N. Amer. Herp., IN". 1842. p. 57. I'l. xv : I'mI. and Kir.i., ( .ii. .s.rpt. X. Amer., 



1853, p. .5'.). 

 Heterodon sinutx .s/oi/is ( ope, Check List X. .\mir. Matr. Kfju.. 1ST5, ji. 13. 



' Bull. U. S. Nat. Mils., No. 3'2, 1887, p. .54. 



