116 KFX'ORDS OF THK AUSTKAMAX MUSEUM. 



i'nloiir iiiarl-iinjs. — Tlie coloui' marking of tlie ventral shields was 

 originally described as yellowisli or Avliite in /'. .v»/k, and peaily-wliite 

 witli a broad biouze-colonred median band in iK fionhilis. The following 

 analysis will shoAV, however, that this colour marking has no value as a 

 specific character. 



Of thirty specimens e^^amined (not counting the six embryos) sixteen 

 agreed most nearly with 1). frontalis. Three of these, including the type, 

 have a distinct median baud ; three have very slight traces of a median 

 band ; one has the ventrals daikly blctched tiansversely, while nine have 

 clear ventials as in D. siita. 



Of six specimens which agree most nearly with D. snta, three have 

 clear ventrals, one has a distinct median band, and two have slight traces 

 of the median band. 



The remaining eight specimens 1 regard as intermediate forms; three 

 of them have the nasal and preociilar in contact on one side of the head 

 and separated on the other ; these all have clear ventrals. Five specimens 

 show a very slight contact between the two shields, and of these, two have 

 clear ventrals, two have a sligiit trace of a median band, while one has the 

 ventrals darkly blotched tiansversely. 



The six embryos also have the ventrals darkly blotched fransveisely, 

 like their mother. 



The colour markings on the head and nape are fairly constant, anil 

 full details of them will be found on the last page. 



Dejiiiitioit of l>ei(isniiia snti( based upon the specimens and desci'iptious 

 referred to in the preceding pages : — 



Diameter of the eye twice its distance fiom the mouLli. Pupil 

 vertically elliptic or round. Rostral much bi'oader than deep, just visible 

 from above. Internasals about half the size of and shorter than the pre- 

 frontals ; both shields ai'e bi'oadei' than long. Fi-ontal once and foui'-fifths 

 to twice as broad as the supra-oculai-, and once and one fifth to once and thi'ee 

 fifths as long as broad, a, little longer than its distance from the end of 

 the snout, shorter than the parietals. Nasal entire: either in contact 

 with the preocular, or separated from it by the junction of the second 

 up[>er labial with the prefrontal. Two post oculars ; temporals 2 -j- 2, 

 the lower anterior of which is wedged in between the fifth and sixth 

 upper labials. Six upper labials, tlie third and fourth entering the eye. 

 Three lower labials are in contact with the auterioi' chin shield, which is 

 about e(|ual in length to the posterior. Scales in 19 rows. Ventrals 

 141-17-. Total ventrals and su b-caiidals 17l-'2<'7. Anal cntii'e, sub- 

 caudals single, 2(J-.S!*. 



I'oloiir. — Light brown above, scales narrowly margined with l)lack or 

 dark bi'own. A broad dark nuchal collar extending onto the head; top 

 of head dark brown, merging into yellow or white on the sides. Side of 

 the head with a black ii-regnlar band which arises on the rostral shield and 

 |)asses through the nostril and lower half of the I've to the lowei- post 



