The Courtship of Ambystoma tigrinum

Abstract

Gerrhonotus scincicauda nanus, new subspecies Type.-Adult male (Mus. Vert. Zool., No. 5402); collected July 1, 1913, South Island, Los Coronados Islands, Lower California, Mexico; collector, A. B. Howell. Diagnosis.-Size small (maximum head and body length among 79 specimens 114 mm., average 93.3 among 49 evidently adult); upper two rows of temporals' sharply keeled, lower rows weakly keeled or smooth, muzzle pointed; one to three rows of scales on upper arm weakly keeled in adults; eight dorsal rows of caudal scales strongly keeled on tail near its base; two or three rows of lateral caudals usually keeled on each side. Number of transverse scale rows reduced in both dorsal and ventral series, especially ventrals (average 60.4); dark ventral longitudinal lines conspicuous in adults, dark brown in color, transverse bands on body dark brown; a wide dark brown stripe extending across temporal region from eye to ear. Range.-Los Coronados Islands (North, Middle, East and South), Lower California, Mexico. Remarks.-This form is closely related to Gerrhonotus scincicauda webbii of the adjacent mainland. It differs from webbii mainly in sizeno overlapping in size could be shown among 49 apparently adult specimens from Los Coronados Islands and 33 from San Diego County. Other differences are seen in the color pattern and the smaller number of transverse ventral scale rows.