關東州小龍山島(蟒島)のマムシに就きて(I)

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Syoryuzan Island (Hsiaolung-shan, Small Dragon Hill) lies about 10 km off the western coast of the Liao-tung Peninsula, South Manchuria; it is situated at 38° 56′- 38° 57′ N. latitude and 120° 58′ E. longitude. This island is also called Uwabami (Mangtao) Is., Snake Is., Tieshan, Iron Is., or Si-hau-shan Island. It is nearly oblong in shape and extends about 1500 m to the north-west and about 600 m to the north-east. This island which is made up of quarzite and sericite schist has an area of about 700 m^2 and measures 214 m in height. On October 10th, 1937, the writer visited Syoryuzan Island with his collegue and made some observations on the habitats and habits of the poisonous snake Agkistrodon halys (PALLAS). This paper deals with the result of these observations and also with the morphological characteristics of the snake. Description: Rostral somewhat broader than high, visible from above, its upper portion which is in contact with internasals is half as wide as lower portion; internasal small, subtriangular, much wider than long, protruded posterolaterally and in contact with upper loreal; internasal suture slightly longer than half of prefrontal suture; prefrontals a little wider than long; frontals longer than wide, nearly as long as its distance from tip of snout to frontals, slightly longer than internasal and prefrontal sutures combined; parietals about 1.6 times as long as wide, longer than frontals, nearly equal to the width of prefrontals combined; parietal suture shorter than frontals; supraoculars shorter than parietals, equalling the width of internasals; anterior nasal larger than posterior one; nostril roundish; loreals 2, upper loreal flat, lower one incurved; facial pit nearer the eye than nostril and surrounded by lower loreal, lower preocular and subfoveal; preoculars 2-2, upper preocular wider than lower one; postoculars 3-3, long and the lowest one separating the 4th upper labial from the eye; anterior temporals 3-3, middle temporals 5-4, lower series of temporals large and nearly hexagonal, the lowest anterior temporal largest, upper temporals small; upper labials 8-8, 2nd smallest, only 3rd entering orbit and broadest, 4th longest and those behind gradually decreasing in size; menthal nearly triangular anterior margin wider than long; lower labials 12-11, 2nd-4th of which are in contact with anterior chin-shields; anterior chin-shields short, as long as their combined width; posterior chin-shields small, being scarcely distinguished from the scales behind; scales keeled in 26 rows on the neck, 23 at midbody, and 17 before the vent, with a pair of apical pits; ventrals 150, subcaudals 41, anal 1; from snout ot vent 627 mm, tail 100 mm. Coloration (in life): The body light greyish-brown above, with a series of large dark brown blotches extending along either side of the dorsum, these blotches irregularly margined with black posteriorly and anteriorly and more or less alternating on the dorsum anteriorly, forming irregular cross-bars posteriorly; belly grey slightly tinged with red; head greyish-brown above, marked with some blackish-brown spots; a conspicuous narrow blackish-brown band extending from the middle part of postocular to angle of the mouth, along the series of temporals and a yellowish line runs along the lower part of this band; upper labials light reddish-brown, excepting the corner of last labial which is black; lower labials whithish-grey. (Description is based upon the male specimen indicated in Table I, no. 3.) In the present research, I examined nine males and four females of the snake from Syoryuzan Island. The lepidosis and the dimensions of Agkistrodon halys are given in the Tables I and II. There are marked differences between the sexes in total length and the numbers of ventrals and subcaudals. The total length of the male ranges from 480 to 784 mm (average 664.2 mm) and 697 to 840 mm (average 743 mm) in the female. The ratio of the length of tail to the total length is c
1938-05-15

關東州小龍山島(蟒島)のマムシに就きて(I)

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