Two ascidians have been collected in the region of Plymouth that do not fit the descriptions of known species sufficiently well to be identified with them. They are species of Trididemnum and Distaplia.These genera are represented in waters around the British Isles only by Trididemnum tenerum (Verrill) and Distaplia rosea Delia Valle. If Trididemnum niveum should be a valid species and not a synonym for T. tenerum as considered by Hartmeyer (1924), it also is probably present. Accordingly, any species that cannot be identified with these forms must either be new, or must represent geographical extensions of species not previously recorded. In this last respect, the possibility of the Mediterranean Distaplia magnilarva reaching the western Channel must be considered. As the following discussions indicate, the conclusions are that the two forms described here cannot be properly identified with any of the above and are to be treated as new species.Trididemnum alleni n.sp. is named after the late Dr E. J. Allen, so long the inspiring and humane director of the Plymouth Laboratory, while Distaplia garstangi n.sp. is so named as a small tribute to Professor Walter Garstang for his pioneering interest in the ascidians of Plymouth waters.Trididemnum Alleni sp.nov.Colonies are usually small, less than a centimetre in greatest length, and about 3 mm. thick. They are brilliantly white, an appearance retained even in preserved specimens of long standing. The surface is uneven. They are commonly attached to Eunicella and larger hydroids such as Antennularia at depths of from 10 to 30 m., and have been recorded with certainty only from the Plymouth area of the English Channel.

中文翻译：

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海鞘 Trididemnum Alleni 和 Distaplia Garstangi，普利茅斯地区的新物种

在普利茅斯地区收集到的两种海鞘与已知物种的描述不符，无法与它们进行识别。它们是三叉戟和迪斯塔普利亚. 这些属仅在不列颠群岛周围的水域中出现三叉戟（维里尔）和蔷薇花迪莉娅·瓦莱。如果柞蚕应该是一个有效的物种而不是同义词T. tenerum正如 Hartmeyer (1924) 所考虑的，它也可能存在。因此，不能用这些形式识别的任何物种必须是新的，或者必须代表以前未记录的物种的地理延伸。在这最后一个方面，地中海的可能性大蝼蛄必须考虑到达西部海峡。正如以下讨论所表明的，结论是这里描述的两种形式不能与上述任何一种正确识别，应被视为新物种。三棱锥虫n.sp。以已故的 EJ Allen 博士的名字命名，他一直是普利茅斯实验室鼓舞人心和人道的主任，而荸荠n.sp。之所以如此命名，是为了向 Walter Garstang 教授致敬，感谢他对普利茅斯水域海鞘的开创性兴趣。三叉戟sp.nov.菌落通常很小，最大长度不到一厘米，大约 3 毫米。厚的。它们呈明亮的白色，即使在保存已久的标本中也能保留这种外观。表面不平整。它们通常附着在尤尼塞拉和更大的水螅，例如触须属在 10 到 30 m 的深度，并且仅在英吉利海峡的普利茅斯地区有记录。