中文摘要：

本文记述淡水涡虫类单肠目Rhabdocoela达氏科Dalyelliidae小达氏涡虫属Microdalyellia一新种,广东小达氏涡虫Microdelyellia guangdongensis Wang et Rong,sp.nov.,模式标本由卢彦宏于2013年6月9日采自广东省深圳市石岩水库（22°40＇58″N,113°53＇42″E）;杰氏涡虫属Gieysztoria一新种,七星岩杰氏涡虫Gieysztoria qixingyanensis Wang et Rong,sp.nov.,模式标本由刘旭坤于2014年8月6日采自广东省肇庆市七星岩风景区（23°04＇32″N,112°28＇46″E）。对2个涡虫新种的形态特征作了详细描述,并分别与小达氏涡虫属和杰氏涡虫属近似物种进行了比较。所有标本保存于中国科学院国家动物博物馆。

英文摘要：

Two new species of Dalyelliidae（ Platyhelminthes： Rhabdocoela）,Microdalyellia guangdongensis Wang et Rong,sp. nov. and Gieysztoria qixingyanensis Wang et Rong,sp. nov. are described in this paper.Microdalyellia guangdongensis Wang et Rong,sp. nov.（ Plate Ⅰ： 1- 7）Material examined： Holotype PLA-Mi0001,wetlands of Shiyan Reservoir in Shenzhen,Guangdong province,China（ 22°40＇58″N,113°53＇42″E）,June 2013. Paratype PLA-Mi0002- PLA-Mi0004（ PLA-Mi0002 and PLA-Mi0004,isolated sclerotic stylet; PLA-Mi0003,the whole specimen）. All materials were collected by Lu Yanhong and deposited in National Zoological Museum,Institute of Zoology,Chinese Academy of Sciences（ IZCAS）,Beijing,China.Description： Living adults are 900- 1200 μm long,anterior part of body bluntly rounded,posterior part tapered. Reddish brown spots distribute over the dorsal side.Sclerotic stylet is 130 μm long. Two proximal stalks are about 55 μm and 45 μm long. Base of stylet is connected by stylet cross-connection. Cross-connection stretches backwards along with 2 stalks,which form lateral distal branch and median branch and stout spine.Habitat： The new species was found in wetlands of Shiyan Reservoir in Shenzhen,Guangdong province,China. The altitude is 35 m,and water temperature is 20 ℃.Etymology： The specific name reflects the original place from which the material was collected.Remarks： Through careful comparison,the new species is most similar to two species： M. sillimani Graff,1911,and M. tennesseenisis Ruebush Hayes,1939. The stylet of M. sillimani has the 76 μm lateral distal branch with 4- 7 small spines at one side and 8 small spines at another side. Stout spine is 32 μm long in S-shaped. M. tennesseenisis has the98- 110 μm lateral distal branch with 3- 6 small spines at both sides. Stout spine is flat-triangle-shaped. However,the stylet of M. guangdongensis Wang et Rong,sp. nov. is 130 μm in length with the 70 μm lateral distal branch,which has6 small spines at both sides. Stout spine is 7