【摘要】 <正> 1979年6—7月间,我们在湖北省五峰县大山区进行肺吸虫病调查时,采到多批淡水微小螺类,经整理鉴定,发现三个新种,其中两种查到斯氏并殖吸虫尾蚴。这些新种属于觽螺科的两个属,其中一个系新属。现将新种新属描述如下。所有模式标本均保存在湖北医学院寄生虫学教研室医学贝类研究组。小豆螺属 Bythinella Moquin-Tandon 1855 1.五峰小豆螺(新种)Bythinella wufengensis sp.nov.(图1,2)更多还原

【Abstract】 A survey of paragonimiasis in the mountain region of Wufeng County, Hubei Province,was carried out during June to July, 1979. Many lots of different kinds of minute freshwater snails were collected and studied.Among these specimens, three new species have been identified. Two of them are found as the first intermediate hosts of the lung fluke Paragonimus skrjabini Chen, 1959. The new minute snails belong to two genera of the family Hydrobiidae, namely Bythinella and Wuconckona, the latter genus is new to science. The diagnostic features of these new taxa are given in this report. All these type specimens are deposited in the Department of Parasitology, Hubei Medical College, Wuchang, China. Bythinella wufengensis sp. nov. (Figs.1—2) Diagnosis Shell minute, dull white,slenderly-cylindrical,thin and translucent.Shell surface smooth, with very weak growth lines. Whorls 4—4 1/2,convex,scalariform, increase rapidly in height, but slowly in breadth; last whorl rather large, about two-thirds the length of the shell. Apex blunt. Suture well defined. Aperture round ovate,continuous,with a black margin. Outer lip thin, roundly curved. Inner lip slightly expanded outward,and attached to the body whorl.Umbilicus narrow, chink-like. Operculum elliptical, horny,thin, white and translucent, with radial growth lines. In the radula the central tooth has the formula (4-1-4)/(2-2) There are 8 denticles on the lateral tooth, of which the fourth is larger than the rest. The inner marginal has 18—24 denticles, the outer 25—27. Holotype Length 2mm, breadth 0.86mm; length of aperture 0.82mm, breadth of aperture 0.78mm; collected on July 17, 1979 at the gully of mountain slope just outside the south gate of Wufeng County, Hubei Province. Paratypes Length 1.82—2mm, breadth 0.86—0.88mm; length of aperture 0.70—0.82mm; breadth of aperture 0.68—0.78mm; collected with the holotype. Parasite Paragonimus skrjabini Chen.1959. Discussion The present new species is closely related to Bythinella ckinensis Liu and Zhang 1979, but differs from the latter by its slenderly-cylindrical shape, much larger size, inner lip somewhat reflected and attached to the body whorl,and by its radula formula:(4-1-4)/(2-2); 3—1—4; 18—24; 25—27. Bythinella wantanensis sp. nov. (Figs. 3—4) Diagnosis Shell minute, thin. cylindric ovate and semitransparently white.Shell surface rather smooth, with very weak growth lines. Whorls 4—4 1/2,each of which well inflated and scalariform, body whorl very large,occupying about 71％ of the length of the shell. Apex very obtuse. Suture well impressed.Aperture rather large, widely ovate and peristome continuous, with a dark edge. Outer lip thin, quite regularly arcuated. Inner lip slightly expanded outward,without tooth.Umbilicus narrow,slit-like. Operculum elliptical, thin, corneous, translucent, with radial growth lines. In the radula the central tooth has 7 denticles, of which the median is the strongest. There are 4 basals, that is, the formula is (3-1-3)/(2-2) The lateral tooth is elongated and has 7—8 denticles.The inner marginal has 18—22 denticles and the outer 24—26. Holotype Length 2.2mm, breadth 1.2mm; length of aperture 0.98mm, breadth of aperture 0.82mm;collected on July 15, 1979 at Wantan, Wufeng,Hubei Province. Paratypes Length 1.9—2.3mm, breadth 0.94—1.2mm; length of aperture 0.97—1mm,breadth of aperture 0.79—0.86mm, collected with the holotype. Parasite Paragonimus skrjabini Chen, 1959. Discussion The new species is similar to Bythinella nipponica Mori, 1937 distinguished by the following features: much larger size; aperture widely ovate, peristome continuous, with a dark edge;outer lip not extended outward; inner lip slightly reflected, without tooth; and the radula formula:(3-1-3)/(2-2);7—8;18—22;24—26. Wuconchona gen. nov. Diagnosis This new genus is near to Bythinella Moquin-Tandon 1855 and Halewisia Davis 1979, but differs from both in the following characteristics:(1)The shell is short conical, minute, thin, smooth, subtransparent, and chestnut brown;(2)The aperture has a peculiar form, its shape is somewhat ovate,peristome continuous, outer margin with an acute angle at the upper, inner margin slightly reflected outward but not attached to the body whorl;(3)The operculum is corneous, thin,semitransparent, elongate ovate, yellowish-brown, with radial growth lines, its salient feature is with an elongate ovate ring of spiral lines near the inner margin; the nucleus excentrically situated on the inner side of the ring; (4) The tentacles are long and slender in the living specimens but thick and flat in the alcohol-fixed specimens, its length is equal to snout; (5)The eye-spots are larger,ovate but not protruding, and situated in a little front of the base of the back of tentacles;(6) The snout of animal is blunt and there is a deep split at the middle part of snout;(7)The verge is flat and rounded, long and thin, and is situated on the neck,turning it from the right to the left, and its end is pointed and curved;(8)With the exception of head and foot,all soft parts is covered with dark color. The new genus is named in honor of Prof.Hsien-wen Wu, the famous ichthyologist,member of the Division of Biological Sciences, Academia Sinica and the director of the Institute of Hydrobiology, Academia Sinica. Type species Wuconchona niuzhuangensis Kang, sp. nov. Wuconchona niuzhuangensis sp. nov. (Figs. 5—7) Diagnosis Shell minute, thin, translucent, and short conical. Surface smooth, chestnut brown, with very fine growth lines. Whorls five in number, each of which somewhat convex, increase rapidly in breadth,but slowly in height; body whorl well inflated,occupying about 2/3 of the shell length. Apex acute. Suture distinctly constricted. Aperture ovate, peristome continuous. Outer lip thin, simple, with an acute angle at the upper. Inner lip slightly expanded outward, but not attached to the body whorl, and under high magnification a rift may be seen between them. Umbilicus narrow. Operculum elongate ovate, yellowish-brown, corneous, thin, semitransparent, with very fine radial growth lines; its outstanding characteristic is with an elongate ovate ring of spiral lines near the inner margin;the nucleus excentrically situated on the inner side of the ring near the broader end; the size of operculum is 0.851 mm by 0.395 mm; it is capable of retraction within the mouth of the shell. With the exception of head and foot, all soft parts is of a dark colour. The tentacles are long and slender in the living specimens but thick and flat in the alcoholic specimens and its length is equal to proboscis.There is a black eye-spot, which is larger and ovate but not projecting,situated at a little front of the base of the back of each tentacle.The proboscis which extends beyond the foot when the animal creeps forward is divided into two parts by a deep split,each part is equal in size. The verge is simple, grayish white, transparent, flat,rounded, long and slender, and is twined on the back of neck, turning it from the right to the left, its end is pointed and curved. The radular band is 3.612 mm in length and 0.413 mm in breadth, the central tooth of the radula has the formula: (3-1-3)/(3-3) The lateral tooth has 6 denticles of which the third is larger than the rest. The inner marginal has 9—10 denticles and the outer 12—13. Holotype Length 2.3mm, breadth 1.1mm;length of aperture 0.69mm,breadth of aperture 0.87mm;collected on July 14, 1979 at Niuzhuang, Wufeng, Hubei Province. Paratypes Length 2.2—2.4mm, breadth 1—1.2mm;length of aperture 0.69—0.84mm, breadth of aperture 0.86—0.89mm; collected with the holotype.更多还原