PROC. BIOL. SOC. WASH. 103(1), 1990, pp. 26-34 A NEW SPECIES OF CUORA (REPTILIA: TESTUDINES: EMYDIDAE) FROM THE RYUKYU ISLANDS Carl H. Ernst and Jeffrey E. Lovich Abstract.— A new species of Asian box turtle, Cuora evelynae, from the Ryukyu Islands is described and compared with C. flavomarginata from Taiwan and southern China. Recognition is based on its pattern of very large light colored pleural blotches (length of blotch at its medial height 49-72% of medial length of pleural) that at their dorsal border coalesce to form lateral stripes in 52% of adults examined, its large light brown plastral blotch which is indented at the bridge, and the usual presence of less than 1 rows of large scales on the anterior surface of the forelimbs. A discriminant function is given that separates C. evelynae from C. flavomarginata. Geological history of the Ryukyu Islands is discussed, in view of speciation of C. evelynae. The yellow-margined box turtle, Cuora flavomarginata (Gray, 1863) occurs in southern China, Taiwan, and the Ryukyu Islands (Iverson 1986). Even though these localities have been long isolated (Inger 1947), no consistent differentiation of these turtle populations has been reported pre-viously. Hsu (1 930) described a subspecies, Cuora f sinensis, from Tungting Lake, Hunan, China, as differing from the nominate Tai-wanese population on the basis of having the anterior border of the plastron obtusely emarginate, each plastral scute with deeply cut parallel lines, each marginal with its pos-terior angle slightly overlapping the next with the degree of overlap most pronounced in the posterior third of the marginals so that the posterior carapacial rim is somewhat serrated, a small notch between the anal scutes, and a much shorter tail. Pope (1 935) commented that with the exception of the longer tail (which may be sexual dimor-phic), all the other characters used by Hsu are either common variants expected in most emydid turtles or differences generally cor-related with age, but Pope thought that until direct comparison between Chinese and Taiwanese C. flavomarginata could be made, it was best to consider the two pop-ulations as distinct subspecies. Tanaka & Sato (1983) have referred to the turtles on the Ryukyu Island of Iriomote as Cuora f flavomarginata indicating an affinity with the population on Taiwan. However, Fang (1934) had critically compared specimens from Taiwan and the Ryukyu Islands with Hsu's diagnostic characters and found that the mainland Chinese turtles could not be differentiated from the insular populations. Recent examination and comparison of C. flavomarginata from these three popu-lations has shown that turtles from the Ryu-kyu Islands can be distinguished from those of the other two populations and represent an undescribed species. Methods and materials. —Sixty-six turtles were examined (Ryukyu Islands, 38; Tai-wan, 14; China, 14). Sexes were determined by the characters given by Ernst & Barbour (1989). Straight-line measurements of each specimen were taken with dial calipers ac-curate to 0.1 mm. Variables included: the greatest carapace length, carapace width and depth at the level of the seam separating vertebrals 2 and 3, marginal width (the dif-
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