Notes on a Poorly Known Blue-Tailed Skink, Eumeces tamdaoensis , from Northern Vietnam

A poorly known skink, Eumeces tamdaoensis Is redescribed on the basis of a newly collected specimen from the northern part of Vietnam. The species has been allied to the fasciatus group of the genus iEumeces, but has closer relationship to the East Asian members of the obsoletus group, i. e., E. chinensis and E. kishinouyei. In 1937 Bourret described Eumeces tamdaoensis on the basis of four specimens collected from Tam-dao, northern Vietnam. No additional specimens of this skink have ever been reported thereafter. Two subsequent authors (Fitch, 1958; Lieb, 1985) listed this species as a member of the fasciatus group, which is one of Taylor's (1936) intrageneric groups. However, they did not provide the specific features of this species, probably because they failed to gain access to the original description. Due to unavailability of the publication in which Bourret's (1937) description appeared (i. e., Bulletin Generale de 1'Instraction Publique, Hanoi), this species has been one of the least known members of the genus Eumeces. In 1982 a peculiar specimen of Eumeces was collected from northern Vietnam. Since then we fortunately obtained a copy of Bourret (1937) through the courtesy of Dr. R. Yoshii, and we identified the specimen as E. tamdaoensis, since even details of the morphology of the specimen agreed well with the original description of that species. Although Bourret (1937) compared the species only with E. elegans and insufficiently diagnosed it, we found that it is a valid species from comparisons with other East Asian species of Eumeces. In this paper we redescribe this poorly known species, Eumeces tamdaoensis, based on the newly collected specimen as well as the original description. We further discuss the taxonomic relationship of this species to the other East Asian Eumeces species. MATERIALS AND METHODS Specimen examined. Eumeces tamdaoensis, ZIL (Zoological Institute of Leningrad) 19806, a male juvenile, collected from Kuk-Fiong, Hasonbinh Province, northern Vietnam (Fig. 1), in July 1982 by I.S. Darevsky. In describing the scutellation of the FIG. 1. Known localities of Eumeces tamdaoensis. Closed circle indicates the type locality, Tam-dao, and open circle Kuk-Fiong, Hasonbinh Province, Vietnam. Accepted 13, Jul. 1987 HIKIDA & DAREVSKY-VIETNAMESE SKINK 11 head we followed the terminology proposed by Taylor (1936), which is different from that of Bourret (1937); Bourret's `internasale' and 'postnasale' correspond to Taylor's (1936) postnasal and posterior part of nasal, respectively. Several characters, which we measured or counted here on the present specimen, were not mentioned in the original description of Eumeces tamdaoensis, and therefore provide more detailed description of the species. Eumeces tamdaoensis Bourret 1937. Eumeces tamdaoensis Bourret, Bull. Gen. Instr. Publique (Hanoi) 9, p. 19, fig. 5, pl. 1 (c, d), (terra typica : Tam-dao, northern Vietnam); 1958, Fitch, Univ. Kansas Publ. Mus. Nat. Hist. 8 (1), p. 11; 1985, Lieb, Nat. Hist. Mus. Los Angeles County Contr. Sci. (357), p. 13. Four syntypes were reported to be deposited in the Laboratoire des Sciences Naturelles de 1'Universite Indochinoise, Hanoi (Bourret, 1937), but the present location of these specimens is unknown. Diagnosis. -A large five-lined and bluetailed skink of the genus Eumeces. Adult with SVL of more than 110mm. Bifurcating line lacking on parietal region even in juvenile but remaining on snout. Postnasal present. Postmental divided. Nuchals usually two on each side. Lower secondary temporal triangle. Midbody scale rows 22-24. No irregular femoral scale patch. No keels on postanal scales. Paravertebral scales 38-40. Fourth toe subdigitals 17-19. Description. -Snout rounded, rostral visible above triangular (Fig. 2). Supranasal moderately enlarged, but smaller than prefrontal. Frontonasal large, in contact with anterior loreals. Prefrontal slightly smaller than frontoparietal, in contact with anterior and posterior loreals, first FIG. 2. The fifth specimen of Eumeces tamdaoensis (ZIL 19806) from Kuk-Fiong, Hasonbinh Province, Vietnam. Scutellation of head, femoral, and caudal regions. Lateral (A), dorsal (B) and ventral (C) views of head, and posterior view (D) of right femoral region and caudal region (E). superciliary and first supraocular, longest suture with frontonasal. Frontal moderate, much longer than its distance from tip of snout, slightly narrower posteriorly, in contact with anterior three supraoculars. Frontoparietals longer than wide, forming a median suture equal to half their length. Interparietal less in area than frontoparietals, round behind, in contact with nuchals, slightly narrowed posteriorly, as long as wide in young, nearly twice as long as wide in adult. Parietal large, greatest width about three fourths of length. Nuchals two pairs. First postnuchal scale in second row slightly larger than following scales. Nasal moderate, divided, posterior portion behind nostril as large as anterior portion. Postnasal present. Anterior loreal as high as posterior. Posterior loreal three fourths as high as long, touching two supralabials but rarely divided into anterior and posterior part (ZIL 19806, Fig. 2A). Presuboculars two. Supraoculars four. Supercilaries nine. Pre12 Jpn.J.Herpetol. 12 (1). 1987 ocular small, followed by small scutes. Postoculars two. Postsuboculars four. Primary temporal large, rectangular, broadly in contact with two secondary temporals. Upper secondary temporal elongated, with sides nearly parallel and posterior edge round. Lower secondary temporal larger in area, posterior end round without notch. Tertiary temporals small, following behind secondary temporals, scarcely differentiated from suprauricular scales. Supralabials eight, composed of five smaller preorbital elements and three larger postorbital. Last supralabial much larger than preceding ones. Lower eyelid with three large plates separated from presuboculars and postsuboculars by two or three rows of granules. Two superimposed postlabials following last supralabial, separating it from ear opening. Two auricular lobules in anterior margin. Mental enlarged with labial border greater than rostral. Postmental divided, posterior larger. Three pairs of chinshields. Enlarged postgenial following third chinshield. Anterior inner edge of postgenial bordered by a scale wider than long. Body scales parallel on side of dorsum, dorsal scales of median row slightly larger than adjoining lateral scales. Scale rows around middle of body 22-24, normally 24. Scale rows in constricted portion of neck 26. Paravertebrals 38-40. Subcaudals strongly widened, 9 scale rows encircling tail at level of tenth subcaudal. No keeled scales in postanal region. A median pair of preanals very large, smaller outer scales overlapping inner. Outer wrist tubercle prominent. Finger lamellar formula 610-13-13-8 on left side, 6-1 1-13-13-8 on right. Patch of enlarged irregular scales absent on posterior femur. Scales on outer side of sole flat, imbricated. Toe lamellar formula 6-10-15-18-13 on left side and 5-11-15-19-13 on right. Intercalated series of digital scales on only