CADUCIBRANCHIATA AMBLYSTOMATIDAE A. MAVOET1UM. 633 



latter slightly separated medially, and concentric with maxillary series. On 

 this character, preserved in a stage of all allied species without branchiae, 

 I proposed the genus Camarataxis, the validity of which can only be estab- 

 lished when the development of all our Amblystomas is known. It is a 

 stage nearer the larval condition than the transverse series of A. opacum, 

 while the A-shaped series of A. luridum is intermediate. Cope. 



Several specimens of this interesting animal are contained in my collec- 

 tions ; Nos. 455, 456, 5 , from Jacob's Well, nearly on the boundary be- 

 tween Arizona and New Mexico, and No. 491, 3 , from water holes in the 

 San Francisco Mountains. The foregoing is Professor Cope's notice of 

 these specimens. They are still in the Siredon stage, though they have 

 attained a length of six or eight inches, and were confined to the water ; on 

 being exposed to the air, the skin dried with remarkable rapidity, .but would 

 soon regain its natural condition upon re-immersion. They lived for a half 

 hour or so in the air. The color in life was shining-green above and sil- 

 very greenish-white beneath, shading into yellowish about the head and 

 gills, with a few obsolete black spots on the head and back. The now well- 

 known variations in color of this wide-ranging species have necessitated the 

 reduction to synonyms of several species at one time current as valid. 

 Specimens which I lately procured in the northern portions of Dakota and 

 Montana, where they were common in suitable situations, were darker in 

 color than these, more boldly blotched with black, and showed no yellow- 

 ish hue. They had all completed the metamorphosis at a length of three or 

 foiu- inches, and were often found in damp places at a distance from water. 



Amblystoma trismptum, Cope, Proc. Acad. Nat. Sci., Phila., 1867, 194, 

 from the Ocate River, New Mexico, is a species which may be expected to 

 occur in Arizona. 



