190 ANNALS NEW YORK ACADEMY OF SCIENCES 



of the present survey it was found to be abundant everywhere, up to an 

 altitude of at least two thousand feet, but strictly confined to open fields. 



Anolis krugi Peters 



The following localities are represented by sixty-two specimens in the 

 collection : Ad juntas, Aibonito, Coamo Springs, Maricao, and El Yunque. 

 Anolis krugi is confined to Porto Eico. In Porto Eico it is confined 

 largely to the coffee belt, extending beyond it only where similar habitat 

 conditions occur. It is directly related to the more widely distributed 

 Anolis pulchellus and is probably derived from it. The specimens re- 

 corded from Guanica by Fowler (1918, Papers Dept. Marine Biol., 

 Carnegie Inst., XII, p. 11) prove on re-examination to be A. pulchellus. 



In sixty specimens, the number of loreal scales in a vertical row is 

 four in one specimen, five in thirty-four, six in twenty-three, and seven 

 in two. The number of scales between the occipital and the supraorbital 

 semicircles varies from one to six — one in one specimen, two in eighteen, 

 three in twenty-five, four in thirteen, five in two, and six in one. The 

 supraorbital semicircles are in contact in two specimens, separated by a 

 single scale row in thirty-four, by two scales rows in nineteen, and by 

 three in five. This species is often difficult to distinguish from A. 

 pulchellus without direct comparison; the color of the dewlap in life, 

 orange instead of crimson, is distinctive. In alcoholic specimens the 

 narrower band of enlarged dorsal scales is the most satisfactory character 

 for separating the two. Other characters are at best comparative, useful 

 only for a series of specimens. 



Stejneger distinguished Anolis krugi as characteristic of the inter- 

 mediate altitudes, from five hundred to fifteen hundred feet. The speci- 

 mens in the present series from Coamo Springs are from an altitude of 

 less than three hundred feet, while specimens from Aibonito reach an 

 altitude of at least two thousand feet. The specimens from Coamo 

 Springs supply the clue to the determining factor in the distribution of 

 the species, for at that locality it was abundant among the ferns and vines 

 of the moist, dark gorge back of the bath-houses and was found nowhere 

 else. At Aibonito and Maricao, Anolis pulchellus was found on the bare 

 hilltops or in open fields, while a few steps within the borders of the 

 coffee plantations only A. krugi was to be found. Moisture and shade, 

 therefore, are the habitat requirements of Anolis krugi. Anolis crista- 

 tellus and Anolis gundlachi have an exactly parallel distribution. 



