CUYPTOBLEPHARUS PLAGIOCEPHALUS. 221 



Should their identity be established beyond any reasonable doubt, 

 investigations on that subject are not to end there. It will then become 

 of paramount importance to look back into the past history of the coun- 

 tries where the species now occurs, with a view to ascertain, if possible, 

 as to whether it is indigenous to those countries or therein introduced. 



Dumeril and Bibron describe four varieties of coloration ; the speci- 

 mens before us agree with their second variety : the only one with 

 which we are thoroughly acquainted. We believe it to be the one ori- 

 ginally observed by Peron, and we restore the specific name proposed 

 by him. We have made such a selection of the synonyms as in our 

 judgment can rightly be assigned to it, leaving it with future investi- 

 gations to decide on the identity or differences of those we have set 

 aside. 



On a sketch colored from living specimens obtained at Otaheiti, 

 in September and October, 1839, the upper surface of the head, 

 neck, body, tail, limbs, and sides exhibits a golden hue, variegated with 

 black. A narrow golden streak, margined on either side by a black 

 line, may be traced along the upper part of the flanks, from the supra- 

 ocular region to the base of the tail. Beneath, the color is of a uni- 

 form dull white ; sometimes bluish-grey. The specimens in alcohol, 

 collected at the Sandwich Islands, present the same general pattern 

 of coloration, with the exception, that the inferior surface is of a 

 greenish-yellow. The golden hue of the upper regions, if it really 

 existed, has left behind it an olivaceous tint. 



Log. — Specimens were collected at Otaheiti and at the Sandwich 

 Islands. 



Plate XXVI, fig. 17, represents Cryptohhijharus plagioceplialus, size 

 of life. 



Fig. 18, is an upper view of the headj 

 Fig. 19, a profile; and. 

 Fig. 20, an under view of the same region. 

 Fig. 21, exhibits the left hand from above; 

 Fig. 22, the same hand from beneath. 

 Fig. 23, a group of dorsal scales. 

 Fig. 24, a group of abdominal scales. 

 Figs. 18-24, are somewhat magnified. 



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