Identification of the Black-headed Snakes (Denisonia) 

 within Victoria 



by 



A J Covi ntky' 



I he elapKt snake genus Dcnistmia 

 (sensu Boulcngct, IK'Ki) contains 

 over twenty Australian species, includ- 

 ing a numhci- which hear a strong 

 superficial resemblance in that they 

 are relatively small (seldom CXCCCd- 

 mg 700 mm), have light brown 

 bodies, and black heads. f ; or this 

 reason these species are often con- 

 tused. However, there is no doubt 

 thai the similarities ol some are due 

 to convergent evolution, and thai the 

 group is poly phvletie. 



This article discusses the Vicloiian 

 species of black-headed snakes belong 

 ing to the genus Dciusoniu, ami OOD* 

 SorvatiVC taWWOXTjiC conclusions are 

 made in an allempl to aid the identi- 

 fication of the species and help 

 resolve some of the confusion sur- 

 rounding them. It is recognised, how- 

 ever, thai an Australia-wide revision 

 is necessary before final tavonomic 

 conclusions can be made. It should 

 he pointed out thai juvenile speei 

 mens of the Brown Snakes, Ihnmnuu 

 /i w<7m and DtfMTNMJfS nutfathsj which 

 also have light brown bodies and 

 black heads occur throughout Vic- 

 toria, t hese can be separated very 



easily EiOtjl the species under discus- 

 sion, 111 that Di'iHimuii has dtvtdfcfl 

 anal and subeaudal scales, while the 

 black -headed Ut iiiuuiui species have 

 'ingle anal and subeatidals. 



Rawlinson (IM7I) published | 

 eheckhsi ol the reptiles known k< 

 have been collected in Victoria. I his 

 list includes live species ol black 

 headed Dcm\oiiiu, vi/. I), bn-vicmnk 

 Mitchell. Wi, /?. fiagdllum (McCnv. 

 IK7S). D gdttlitli ((>ray. 1X41), 0 

 nifWStffeiHl <K relit, IK6 l >), and I) 

 suui (Peters. 1863). 



Keeenl soiling and checking of 

 specimens m the National Museum of 

 Victoria revealed that the Victorian 

 snakes previously identified as /). 

 hn-viitunkt and D. ttfgro&tfjGta .ire 

 conspeeific (referable to D. hrevi- 

 (inula) and that Vicloiian specimens 

 relerred to 0, fOUUH belong to /) 

 dwM-ri. Thus it appears that thei 

 aie only four species of hlack-headc 

 snakes of the genus l)cni\tntiti in Vi 

 loria, and these are P. hivvinum 

 Mitchell, 1051, /). lias,', Hum (MeCuy, 

 I87S). D. thvycri Worrell, 1956, and 

 I). Mtu, (Peters, 1863) 



Key To Tin .Spkiis H>i ni> IN Victoria 



1 Black head patch divided 



Black head patch undivided 

 2. Scales in 19 rows 



Scales in 15 rows 

 T Dark vertebral stripe present 



Dark veitcbral stripe absent 



fhiy, Hum 

 I 



hn vit undo 



304 



•Nj.t.m.1 Museum ,.l V.U.Kia. 



Vict Nat Vol 8! 



