514 PROCEEDINGS OF THE ACADEMY OF [Sept., 



island, and where but a few examples are studied from each locality, 

 it is but the application of the most elementary arithmetic to dem- 

 onstrate that a small gap exists betAveen the two groups. Where these 

 two groups are recognized in taxonomy, and where the series increases 

 and the gap disappears, then but one criterion is left by which the 

 determination of a specimen may be accomplished — namely, the 

 locality label. 



Elaps spixii (Wagler). 



Type. — Elaps heterochilus Mocquard.^ 



Mus. d'Hist. Nat., No. 87-122. Brazil. Total length 553, tail 

 43 mm. 



Squamation. — Scales in 15 continuous rows; gastrosteges 209; anal 

 entire; urosteges 29 pairs, the 3d to the 8th, and the 24th entire. One 

 preocular and two postoculars; six supralabials, the third and fourth 

 entering the eye. 



Coloration. — Thirty-six subequal black rings; distinct arrangement 

 in triads is present only in the first three sets, posteriorly the inter- 

 spaces between the sets are distinguished by being a trifle wider and 

 by having the red scales with a slightly smaller black spot at the tip. 



Anatomy. — Diameter of the eye 1.6 mm., its distance from the 

 mouth 2 mm. 



There are nearly forty species of Elaps, and all have seven supra- 

 labials. There is no genus of anything like this size with so uniform 

 a count. The reduction to six supralabials seen in this specimen is 

 caused by the fusion of the normal first and second; this fused shield 

 shows on its lower margin an indenture and a very short suture ex- 

 tending upward. The reduction in the number of infralabials is due 

 to the fusion of the normal first and second; the right shield has a 

 short incisure from the oral rim. These dents and short sutures 

 indicate the position of the normal line of separation. The temporals 

 are irregular ; the anterior shield on the right side being fused with all 

 the lateral cephalic shields as far back as the last labial; the posterior 

 temporal on the left side is fused with the shield that normally inter- 

 venes between it and the azygos plate l)ehind the parietals. 



E. heterochilus has been based upon a specimen having a number of 

 the normal shields fused and others not completely divided. 



M. Mocquard suggested that these conditions might be abnormal 

 when he wrote, "La disposition observes ici pourrait done n'etre 

 qu'une simple anomalie." 



U. S. F. S. Albatross, July 6, 1913. 



9 1887, Bull. Soc. Philom., (7), XI, p. .39. 



