Hypermecaspis(三叶虫)的蜕壳

在中国，只在浙江江山早奥陶世印渚埠组顶部的Ａｒｅｎｉｇ期发现有Ｈｙｐｅｒｍｅｃａｓｐｉｓ ａｓｉａｔａ Ｈａｎ一个种。文中的Ｈｙｐｅｒｍｅｃａｓｐｉｓ采自江山横塘塘及竹余，和江山城北４ｋｍ公路两侧的印渚埠组顶部。仅有少数标本保存有头盖，大部分只保留有自由颊、胸与尾，极少相对移位，应为原地理葬标本，所发现的Ｈｙｐｅｒｍｅｃａｓｐｉｓ几乎全为况壳标本。面线起机能作用，面线裂开，头盖与胸部分离，头盖 表

TECHNIQUES OF EXUVIATION IN HYPERMECASPIS (TRILOBITA)

In China, only one species of Hypermecaspis , i. e. H. asiata Han was found from the top of Yinzhufu Formation of the top Lower Ordovician in Jiangshan, Zhejiang Province. The psesent specimens were collected from the top of Yinzhufu Formation at three localities in Jiangshan area, viz. Hentang, Zhuyu and a place 4 km north to Jiangshan. In these specimens, mostly the librigena, thorax and pygidium are preserved, only a few with cranidia, and few displaced relatively, therefore these specimens belong to autochthonous remains. Almost all the Hypermecaspis are moulting specimens. Serving as the function of moulting, the facial suture split, the cranidium was separated from the thorax, and was turnd; sometimes the thorax split and part of thoracic segments were turned, which reflects during moulting the thorax bulged, and then flattened; when the facial suture split, the new animal crawled forward carrying the old cranidium. The exuvial model of Hypermecaspis could be a major one in micropygious type trilobites. The exuvial model of trilobites interpreted by McNamara and Rudkin (1984) and Heningsmoen (1975), is not similar to this case.