【摘要】 <正> 拟钉螺属(Genus Tricula)是Benson于1843年根据采自喜马拉雅山西边阿萨姆(Assam)的标本创立的新属,模式种为山拟钉螺(Tricula montana Benson,1843)。但从那以后,模式种便未再发现(Rao,1928);我国有无山拟钉螺,尚属疑问。拟钉螺在分类上隶属于腹足纲(Gastropoda),觿螺科(Hydrobiidae),拟钉螺亚科(Triculinae)。这些螺更多还原

【Abstract】 During the years 1979 to 1981 surveys on paragonimiasis were carried out in Wnfeng County, Xingshan County and Bnshi County, Hubei Province, and lots of freshwater minute snails were collected. Among the collections, we come across three new species belonging to the genus Tricula of Hydrobiidae. Of which, two are found to be the first intermediate hosts of I’aragonimus skrjabini Chen, 1959. The diagnostic features of these new taxa are given as follows. The types are preserved in the Department of Parasitology, Hubei Medical College, Wuchang, China.Tricula pingi sp. nov. (Figs. 1-5)Diagnosis The shell is minute, elongate-conical, thin and opaque. The shell surface is smooth and without ribs, but stained with dirt. The color in life is darkish brown, and sometimes the body whorl is tinged with yellowish-brown. There are 6-7 gradually and evenly growing whorls, each of which is well convex, so that sutures arequite impressed. The spire is rather high, consisting of 5-6 whorls, each nearly 11/2times its preceding one in length. The apex of the spire is blunt and rounded, and the protoconch is minutely mamillate. The body whorl is not very tumid, its lower portion reduced, whose length is about equal to, or a little longer than half the length of the shell in ventral view. The penultimate and antepenultimate are band-shaped in both dorsal and ventral views. The aperture is pyriform, continuous, with dark margin, its upper portion is very narrow but lower portion is wide and rounded. The outer and inner lips are thin and simple. There is a wide rift between inner lip and body whorl. The upper portion of inner lip is with a small tooth, which is the most charac- teristic feature of this species. The umbilicus is narrow and chink-like. The operculum is yellowish-brown, corneous, opaque, ovate, blunt and rounded at both ends, and slightly thickened from the edge to the nucleus, and is capable of retraction within the mouth. The animal is of a bluish-black, and has long tapering tentacles, which when fullystretched are about 31/2 times as long as the snout. The eyes are small and black, situated at the outer base of dorsal side of the tentacles. The mantle edge is smooth and without papillae. The verge is simple, light yellow, slender and long, and is coiled up at the back of the neck near the right, and its end is pointed. On examination of the soft parts, I have discovered a snail with two penes twined on the back of the neck. I look upon that as most unusual and so far unrecorded. Both shell and soft parts of this snail are normal, and only the apex is decollate. The snout is wide and short, and slightly emarginate in front. The sole of the foot is rectangular when backstroke, but its antero-lateral angles are not acute and the postero-lateral angles more rounded. The radula is band-form, 0.6 mm in length, 0.1 mm in breadth. The central tooth has 5 denticles, a larger median with a smaller one adjacent to this and the outer still smaller. The basals in the central tooth are 3 on each side; the formula thus becomes2-1-2/3-3The lateral tooth has a strong cusp and one minute cusp on the inside of this and 4 on the outside. The inner marginal bears 9 denticles and the outer 11.Holotype Length 4.35 mm, breadth 1.65 mm; length of aperture 1.56 mm, breadth of aperture 0.95 mm; collected on October 25, 1981 at Shenjiabao about 30 miles south of Yuguan, Wufeng, Hubei.Paratypes Length 2.89-4.43 mm, breadth 1.2-1.65 mm; length of aperture 0.91-1.65 mm, breadth of aperture 0.64-1 mm; collected on September 10, 1979 and in October to December, 1981 from Shenjiabao, Wufeng, Hubei.Parasite Paragonimus skrjabini Chen, 1959.Discussion This new species may be easily distinguished from its congeners by the following characteristics: (1) The adult shells are elongate-conical, thin, smooth, without varix, darkish-brown, and covered with dirt; (2) The upper portion of the inner lip with a small and distinct tooth; (3) Based upon the measurements of 20 shells, the length is 2.89-4.43 mm, the width is 1.2-1.65 mm; the ratio of width to length with an更多还原