中国近海蛇首螺科和两新种的研究

STUDY ON COLUBRARIIDAE FROM CHINA SEAS,WITH DESCRIPTIONS OF TWO NEW SPECIES

蛇首螺科(Colubrariidae)是前鳃亚纲、中腹足目、嵌线螺总科中的一个科,对此科的分类位置学者间各有不同,有的放在嵌线科,有的放在蛾螺科或单独一科。Fischer(1887)和Thiele(1931)将Colubraria属放在法螺属Charonis中的Sectio,迄今仍然如此,但多数是放在嵌线螺总科中,18世纪记载此科种类多数放在 Triton属内。 此科动物生活在潮间带和潮下带岩石、沙质和泥沙质的海底,有不少种类生活在热带或亚热带水域。在中国沿海分布的北限为浙江南部。

The present paper deals with Colubrariidae(Mollusca: Prosobranchia) collected from the China coast by the Institute of Oceanology, Chinese Academia of Sciences in the past years. Of the 7 following identified species belonging to 2 genera, 2 are considered as new species and 1 is first recorded in China(Marked with asterick). Colubraria cumingii(Dohrn,1861)C. castanea Kuroda & Habe 1952C. clathratus Sowerby, 1883C. tortuosa (Reeve, 1844)C. tumida sp.nov.C. tchangsii sp. nov.Antemetula mitrella (A. dams & Reeve, 1849).Colubraria tumida sp.nov. (fig. 5) Holotype locality. South China Sea(20°00′N,108°00′E),60m depth. 1960,04,13.Paratype locality:South China Sea(17°50′N,108°00′E), 85m depth. 1959,04,16.Holotype (No. M38391) and Paratype (No. M38392) are deposited in the Institute of Oceanology, Academia Sigica.Description: The shell is fusiform, not thick, solid, whorl sinflate, about 10. The pro-toconch always eroded, spire turride and body whorl ventricose. Outer surface except for the protoconch and the next layer glossy smooth, others, with numerous longitudinal and transveres fine ribs, the crossing point of which become small slightly granular protrusions on the surface. Varices at every whorl; yellowish in colour (dead shell) at the surtace and with interrupted distinct brown wave striae, two on the penultimate, and four on the body whorl. The aperture narrow, elongated and outer margin with varices; minute denticles inside outer lip; inner lip thin, smooth, anterior canal short, curved backward. Measurement: L.36.5mm 33.0mmW.12.5mm 11.2mmEcology: Found on muddy and sandy bottom at 60-85m depth.Distribution: Known only from the South China Sea.Discussion: The new species is similar in shape to Triton tessellatus Reeve, 1844, but differs from it by the thinnish shape and brown striae.Colubraria tchangsii sp. nov. (fig. 6)Holotype locality: South China Sea(19°15′N,111*00′E), depth 78m. 1959,01,27.Holotype(No. M38373), deposited in the Institute of Oceanology, Academia Sinica.Description: Shell small, almost fusiform, solid, with about 9, moderately convex whorls; spire turritede; body whorl large; outer surface except protoconch and the next layer glossy smooth, others with numerous longitudinal and transvers, fine ribs, the crossing point of which become small granular protrusions on the surface; sipral ribs 11 on the penultimate, 42 transverse ribs on the body whorl, varices at every whorl in different places, surface greyish white in colour, with interrupt indistinct brown lines on the centre whorls. The aperture inside white, and with purplish spot in the anterior, and with varices on the back margin; outer lip with minute denticles. Inner lip smooth, with a thin plate on the edge, and plicate in the centre of the columella; anterior cannal short, narrow, curved back ward. Measurement:L. 26.5mm W.9.0mmEcology: Eound on sand and muddy bottom at 78m depth.Distribution: Known only from the South China Sea.Discussion: The new species is similar in shape to Colubraria antiquata (Hinds, 1844), but differs from it by the slender shape and the white inside aperture.