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U.S. NATIONAL MUSEUM BULLETIN 2 88 



Variation. — Structurally, there is not much variation in the series at 

 hand. 



In terms of color and pattern the specimens show more variability. 

 Some are quite pale while others are quite dark, but this does not seem 

 to have any geographic significance for our palest and darkest speci- 

 mens came from the same locality. All specimens show some degree 

 of mottling on the back but the amount of contrast between the 

 darker mottling and the lighter ground color ranges from almost 

 imperceptible to conspicuous. Here again there seems to be no geo- 

 graphic correlation for the two most conspicuously mottled individuals 

 before us came from the Panama Canal Zone and the Rio Calima in 

 Valle, Colombia. 



Remarks. — While H. rosenbergi is certainly closely related to 

 H. maxima and at first glance seems very similar to it, the differences be- 

 tween the two seem significant and constant. The characteristics indi- 

 cated in the following tabulation should help in distinguishing these 

 two species. 



A single specimen (CJG 2258) collected by the junior author on 

 the Rio Calima was, in life, pale tan dorsally and bright orange along 

 the sides, in the groin, on the anterior and posterior surfaces of thighs, 

 under the arms and feet, and on the webs of both hands and feet. 



The distribution of H. rosenbergi is still a problem (Netting, 1935, 

 p. 15). The species apparently is abundant in northwestern Ecuador 

 and southwestern Colombia; has been recorded from both the Pacific 

 (Rio Chucunague) and Atlantic (Rio Chagres) drainages from Panama; 

 and is here recorded from the Atlantic drainage (Rio Sinii) of Colom- 

 bia for the first time. There are no records of it from the Rio Atrato in 

 Choc6, Colombia, although H. maxima has been recorded there. In 

 view of these records it seems likely that rosenbergi will some day be 

 found to occur in the lowlands of all of western Colombia and all 

 of northern Colombia west of the Maracaibo drainage. 



A detailed life history of this species in Panama has been published 

 by Breder (1946). 



