海南岛陆栖寡毛类二新种记述(寡毛纲:巨蚓科)

TWO NEW SPECIES OF TERRITORIAL OLIGOCHAETES FROM HAINAN ISLAND (OLIGOCHAETA: MEGASCOLECIDAE)

1982年采自海南岛尖峰岭热带原始森林的巨蚓科(Megascolecidae)远盲,属Amynthas蚯蚓二新种:双陷远盲蚓 Amynthas biconcavus sp.nov.和四突远盲蚓 Amynthas tetrapapillatus sp.nov.。文中采用的是Sims & Easton 1972和Easton 1979对环毛属Pheretima订正后的分属系统。

The present paper reports two new species of the genus Amynthas collected from Hainan Island, 18°44’N, 108°55’E, China. Type specimens are deposited in the Institute of Tropical Forestry, Chinese Academy of Forestry Sciences, Guangzhou.1. Amynthas biconcavus sp. nov. (figs. 1-3)Body rather small, length 71-78 mm, diameter 2 mm, segments 102-133. Prostomium 1/3 epilobous. First dorsal pore on 12/13. Clitellum on X1V-XVI, with or without setae. Setae fine, 32-36(Ⅲ), 36-47(Ⅴ), 37-44(Ⅶ), 38-44(Ⅺ), 35-45(ⅩⅩ); 4-5(Ⅶ, Ⅷ) between spermathecal pores, no setae between male pores.Spermathecal pores 2 pairs, on the anterior margin of Ⅶ and Ⅷ, close to ventro-median line, about 1/9 circumference ventrally apart. Male pores about 1/6 ventrally apart, each with a small penis situated in a large elliptical depression.Septa 8/9 and 9/10 absent. Caeca simple, in XXVII XXV. Last hearts in ⅩⅢ. Holan-dric, Testis sacs unpaired, as transverse band. Seminal vesicles small, also transverse band, no dorsal lobe. The first pair of seminal vesicles are contained in the second pair of testis sacs. Prostates, in XVII-XXII or 1/2 XVI-XX, ducts medially thickening, with accessary glands on the cctal end of the prostatic duct. Spermathercal ampulla ellipse, ca. 1-1.2 mm long, seminal chamber long eggplant-shaped.Holotype: 5A. No. 7-1(72 mm long, 2mm wide, 132 segments, Setae: 32(Ⅲ), 40(V), 43 (Ⅺ), 42(ⅩⅢ), 40(ⅩⅩ); 5(Ⅶ, Ⅷ) between spermathecal pores), collected from Jianfen Ridge, Ledong County, Hainan Island, May 1982. Paratype: 5A. No. 7-3(18 specimens), same collodion data as holotype.Remarks: The present species is similar to Pheretima fomella Gates, 1935 but differs from the latter with small penis in a large elliptical depression and character of seminal vesicles.2. Amynthas tetrapapillatus sp. nov. (figs. 1-6)Length 152-165 mm, diameter 4.5-5.0 mm, segments 128-136. Prostomium 1/2 epilo-l)ous. First dorsal pore on 11/12. Clitellum in XIV-XVI, without setae. Setae fine, close and evenly distributed, 82-88(Ⅲ), 93-107(Ⅶ), 88-100(Ⅸ), 89-93(Ⅺ), 86-102(ⅩⅩ); 12-13(Ⅵ) between spermathecal pores, 9-10 between male pores.Spermathecal pores 1 pair, in 5/6, near the dorso-median line, about 1/6 dorsally apart.Male pores about 1/4 ventrally apart, each on a large projected porophore, surrounded by 1-3 circular ridge. Near the porophore, two large, slightly ovoid papillae situated between 17/18 and 18/19 respectively.Septa 8/9 and 9/10 absent. Caeca simple, in XXVII-XXV. Intestine enlarges in XV. Last heart in XIII. Holandric. Testis sacs paired, connected ventrally. Seminal vesicles as transverse band, with dorsal lobe, the first pair of seminal vesicles are contained in the second pair of testis sacs. Prostates, in XVII-XX, ducts curved. Spermathecal ampulla heart-shaped, about 1.8-2.0mm, diverticulum as long as or longer than the main part, zigzag looped near seminal chamber. Seminal chamber ovoid.Holotype: 3A. No. 3-1(152 mm long, 4.5 mm wide, 128 segments. Setae: 88(Ⅲ), 93(Ⅶ), 88(Ⅸ), 89(Ⅺ), 86(ⅩⅩ), 13(Ⅵ) between spermathecal pores, 10 between male pores). Paratype: 3A. No. 3-2(5 specimens). Holotype and paralype were collected from Jianfen Ridge, Ledon County, Hainan Island, in May 1982.Remarks: In considering the character of the first pair of spermathecal pore in 5/6, ampulla heart-shaped, seminal chamber ovoid, and the first pair of seminal vesicles contained in the second pair of testis sacs, the present species is similar to Pheretima muta Chen, 1938. But it can be clearly distinguished from the latter by spermathecal pores near the dorso-median line and near the porophore, and two large slightly ovoid papillae situated between 17/18 and 18/19 respectively.