Patina pellucida occurs in two facies with characteristics of habitat and structure, the latter' affecting mainly the shell. One variety, pellucida, which lives on the fronds of Laminaria, has a smooth, elpngated oval and low shell, which is transparent and brown in colour, with 2-8 blue rays radiating backwards from the summit which is placed at the anterior end; it is normally devoid of either epiphytic or epizoic growth. The soft parts are pigmented because of the translucency of the shell, the radular teeth only slightly worn, and the arrangement of the gut coils adapted to a long, narrow haemocoelic space. The second variety, laevis, lives in caves in the holdfasts of Laminaria, and has a rough, round and usually high shell, though the proportions are more variable than in the variety pellucida. The shell is opaque and brown in colour, with 2-46 blue rays and also red-brown ones more or less regularly alternating with them; it has a central summit and is frequently covered with growths of various sorts. The soft parts are not pigmented, the radular teeth are considerably worn, and the coiling of the gut modified to fit into the rounder haemocoel.The life history may be summarized: the animals breed maximally in winter and spring, the planktonic larvae settling mainly in May as spat about 2 mm. in length. They grow so as to reach a length of about 5 mm. in the following autumn and 10 mm. after a year of sedentary life, becoming sexually mature at 5 mm. length. The majority of the animals die after a settled life of 12 months, but a few linger on into a second year: nearly all these belong to the variety laevis, living a sheltered life within the holdfast of the weed, not exposed like pellucida to the effects of wave action and storm.

中文翻译：

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Patina Pellucida (L.) 的生活史

Patina pellucida 发生在具有生境和结构特征的两个相中，后者主要影响贝壳。一种是透明的，生活在海带的叶子上，有一个光滑的椭圆形和低壳，透明和棕色，有2-8条蓝色光线从位于前端的顶部向后辐射；它通常没有附生或外生生长。柔软的部分是有色素的，因为外壳是半透明的，牙齿只有轻微磨损，肠道线圈的排列适应了狭长的血腔。第二个品种，laevis，生活在海带要塞的洞穴中，具有粗糙、圆形且通常较高的外壳，尽管比例比透明品种的变化更大。壳不透明，呈褐色，有 2-46 条蓝色光线和红褐色光线或多或少有规律地交替出现；它有一个中央顶峰，经常覆盖着各种生长。柔软的部分没有色素沉着，牙齿明显磨损，肠道的盘绕经过修改以适应更圆的血腔。生活史可以概括为：动物在冬季和春季繁殖最多，浮游幼虫主要在可能吐出约 2 毫米。长度。它们生长以达到约5毫米的长度。在接下来的秋天和 10 毫米。经过一年的久坐生活，在 5 毫米处变得性成熟。长度。大多数动物在 12 个月的稳定生活后死亡，但也有少数会持续到第二年：几乎所有这些动物都属于 laevis 品种，在杂草的牢笼中过着隐蔽的生活，