OCR Text |
Show 494 . MR. G. A. BOULENGER ON THE [May 18, In the same year, I had to deal with the genus Sceloporus in the second volume of the ' Catalogue of Lizards,' and, notwithstanding the small material at m y command, felt justified in uniting under one species <S. spinosus, horrldus, and clarkil, which seemed to agree in all respects save the number of femoral pores, viz., 7 to 10 in the first, 2 to 5 in the second, and 12 to 15 in the third; and this character served m e in dividing the species into three forms or varieties. Giinther, in 1890, went even further, and refused to accept the varieties on the ground of a " want of agreement between the number of pores and the distribution of the species." This is partly due to his having mixed up two species under his S. spinosus (see S. acanthinus, p. 497). As a matter of fact, Giinther never examined a Mexican specimen of S. spinosus with more than 13 pores, and the only two that possess more than 10 come from a locality (Tampico) which is not physically separable from Arizona and Sonora, the home of S. magister, to which form they undoubtedly belong. In 1893, Stejneger discovered differences in the scales in front of the ear by which he proceeded to divide the S. spinosus with 7 or more pores into as many as five species, viz., S. spinosus, S. boulengeri, S. clarkil, S. fiorldanus, and S. magister. I will now examine the value of these supposed species. 1. S. boulengeri is based on specimens from Presidio, near Mazatlan, believed to be distinguished by small, comparatively short and broad auricular scales, and a very broad interparietal. As the British Museum possesses 7 specimens from the same locality and collector, I a m in a position to dispose at once of this supposed species by figuring (fig. 2) the ears of two specimens, one of which (a) agrees wdth Stejneger's figure, the other (b) approaching the type of S. spinosus as figured by Bocourt (c), and Auricular scales of Sceloporus spinosus. by giving the following measurements of the interparietal in four specimens each of S. spinosus, S. boulengeri, and S. clarkil; the first figure indicates the length, the second the width:- S. spinosus 5 : 4, 5:5, 4 : 4|, 4 : 4. S. boulengeri .... 5 : 5, 5:5, 4:5, 4| : 5. S. clarkii 4§ : 4|, 4 : 4|, 4 : 4, 4 : 4. There is no difference whatever, in structure or coloration, by which S. boulengeri may be distinguished from S. spinosus. |