12 CALIFORNIA ACADEMY OF SCIENCES [Proc. 30 Ser. 



the frontoparietal separated from the enlarged supraoculars. 

 The less highly colored young males show a single median 

 blue throat patch, as in 5. biseriatus, indicating that the island 

 lizard is more closely related to that species than to vS. occi- 

 den talis. 



The fact that the characters of this form seem to be con- 

 stant on San Miguel while varying toward 5. biseriatus on 

 Santa Rosa and Santa Cruz islands raises an interesting 

 question in nomenclature: Should the San Miguel Island 

 form be regarded as a species or as a subspecies? If these 

 lizards inhabited a peninsula one would use a trinomial for 

 them all, but since they are found on well separated islands 

 the facts seem to be best expressed by the nomenclature 

 adopted above. 



3. Gerrhonotus scincicauda S kilt on. 



Plate VII, Figs. 3-4. 



Gerrhonotus scincicauda Van Denburgh, Occas. Papers, Cal. Acad. Sci. 5, 

 1897, p. 106. 



I am unable to distinguish six specimens (Cal. Acad. Sci. 

 Nos. 3881-3883 and 3896-3898) collected on Santa Rosa 

 Island from the species now known as G. scincicauda; that is 

 to say, the form with fourteen longitudinal rows of scales, 

 single interoccipital plate, large azygous prefrontal, longitu- 

 dinal lines along the middle of each row of ventral scales, 

 and smooth temporals. This clearly is the form to which 

 Baird and Girard applied the name G. scincicauda, but that it 

 is the species originally described by Skilton seems far from 

 certain.^ 



The specimens from Santa Rosa Island all have dorsals in 



fourteen longitudinal series. The number of transverse series 



- _ 



1 Skilton's description, which seems to apply rather to the species afterward named by 

 Baird and Girard Oerrhonotus principis, is as follows: 



' ' Tropidolepis scincicauda, n. s. Slender, tail much longer than body, cylindrical. Dermal 

 plates of the body and tail, carinate above, smooth beneath, verticillate. The carinate plates 

 in nine rows. Color, dusky green above, light ash color below. A row of small dark spots on 

 each flank. Another row of smaller ones along the vertebral line. Some of the dark colored 

 scales on the flanks tipped with a whitish color. Length five to five and a half inches." 



The plate accompanying Skilton's article is so poor as to throw no light on this question, 

 and it seems best to make no change in the nomenclature until some one has examined 

 Skilton's specimens, one of which, according to Yarrow's Catalogue, is No. 3089 of the 

 National Museum collection. 



