616 REPORT OF NATIONAL MUSEUM, 1902. 



sides; on back and flanks a series of narrow blackish crossbars becom- 

 ing obsolete on the lower back, the interspaces filled with roundish 

 isabella-colored spots; lower back similarly spotted, as are also the 

 upper side of the legs; tail above with these spots more faintly indi- 

 cated; underside whitish with a turquoise-blue suffusion on both sides 

 of abdomen and under the tail; underside of thighs pale gray dappled 

 with white round spots like those on the back. 



Variation. — In the large series of specimens before me (58) there is 

 considerable variation in minor structural characters. Thus the num- 

 ber of supereiliaries varies between 6 and 8; the upper labials between 

 5 and 8 (normally 6), lower labials between 5 and 6 (normally 5); the 

 number of supraoculars is fairly constant at 4, sometimes one may be 

 abnormally divided; in one instance the third supraocular is entirely 

 separated from the frontoparietal by granules; the occipitals are of 

 very variable size and shape, the median, perhaps, more often smaller 

 than the next pair than otherwise; the central group of enlarged 

 throat scales, or gulars, is of very variable aspect. The ventrals are 

 nearly always in 10 longitudinal rows, and the transverse rows vary 

 from 34 to 39, averaging about 35. The number of anal plates is by 

 no means limited to 3. Frequently there are 5, two narrower ones 

 being added, one on each side, to the two posterior plates, or even 6 

 when the anterior plate is divided by a transversal suture. Femoral 

 pores, from 12 to 18 on each side; of sixty-seven specimens, three 

 have 12; one, 13; eight, 14; twenty-five, 15; eighteen, 16; eight, 17, 

 and four have 18, the average being 15.4 and the vast majority of 

 specimens having 15 or 16 pores. 



The coloration is still more variable. Specimens with or without 

 white dots, with or without stripes, are found in all localities. There 

 are quite 3^oung specimens with comparatively few markings, but as a 

 rule the spots and stripes become more and more obsolete with age. 

 The pink color of the tip of the snout is also present in a varying 

 degree, many having no trace of this tint. 



Habitat. — The ameiva, or, as this ground-lizard is generally though 

 erroneously called by the natives, the iguana, is common all around 

 the coast line of Porto Rico in the neighborhood of water, salt or fresh, 

 preferably where the ground is sandy or gravelly. In the interior it 

 follows up the river courses, but it does not reach a high altitude. 

 Thus, on the Rio Grande de Loiza the U. S. Fish Commission party 

 found it as far up as Caguas, while on the Rio Grande, de Arecibo we 

 traced it to Utuado. 



This species is also common in Vieques, St. Thomas, and the other 

 Virgin Islands. It is represented in Mona Island by a closely allied 

 form. 



