nulata continued to be employed by the greater number of naturalists for Rösel's Federbuschpolyp, and we find accordingly this little animal so designated by Lamarck, De Blainville, Dumortier, and Gervais. The next question of importance is the determination of the exact relation which the two series of synonyms just enumerated hold to one another. In order to form an accurate opinion on this point, it will be necessary to bear in mind the two variations a and ß, which P. repens has been just described as presenting. Now, I believe, the "Corallenartiger-Kammpolyp" of Schäffer to correspond to the P. repens var. a of this monograph, while the "Federbusch-polyp" of Rösel corresponds to the variation ẞ, and if so, the two animals must be viewed as identical in species. Müller believed them to be distinct, but he founded this opinion on certain characters in the figures and description of Rösel, some of which were obviously erroneous, while others afforded no grounds for specific distinction at all. The distinction, therefore, drawn by Müller is nugatory, and the specific name campanulata, applied by Blumenbach to Rösel's animal, and adopted by subsequent writers, is applicable to no distinct species, and must therefore be expunged. If the above criticism be admitted-and it is what I have arrived at after a very laborious examination-the synonyms of P. repens will stand thus: 1781. Der polyp mit dem Feder-busch. Eichorn, Naturg. der Kleinst. Wasser(Original figure.) thiere, tab. 4. 1789. Tubularia repens. Gmelin, Linn. Syst. Nat., p. 3835. 1804. Tubularia lucifuga? Vaucher, Bull. de la Soc. Philomat., ann. xii, No. 81, pl. 19, figs. 4, 5, 6, 7, 8.* (Original figures, bad.) 1806. Tubularia repens. Turton, Linn. Syst. Nat., vol. iv, p. 668. 1816. Plumatella lucifuga? Lamark, An. sans Vert., 1st edit., vol. ii, p. 108. 1816. Naisa repens. Lamouroux, Pol. flex. p. 223. 1821. Naisa repens. Lamouroux, Expos. Méth., p. 16. (Not the figure tab. 68, f. 2, 1824. Naisa lucifuga? Deslongchamps, Encyc. Méth. Zoophytes, p. 562. 1828. Alcyonella, tertius evolutionis gradus. Raspail, Mém. de la Soc. d'Hist. Nat. 1831. Alcyonella stagnorum. Ehrenberg, Symb. Phys. Evert. Dec. 1, Pol., fol. a. * Figs. 9 and 10 evidently belong to T. repens on the same Plate, and are transposed by an error of the engraver, while figs. 4 and 5 belong to T. lucifuga, though by a similar error they are placed with T. repens. 1836. Plumatella lucifuga? Lamarck, An. sans Vert. 2d edit., vol. ii, p. 124. 1848. Plumatella campanulata. Van Beneden, Recherches sur les Bryoz. fluv., p. 20, pl. 1, figs. 5, 6, 7, Mém. de l'Acad. Roy. de Belg. (Original figures.) 1849. Plumatella repens. Dalyell, Rare and Remark. Anim. of Scotland, vol. ii. (Original figures.) 1851. Plumatella nitida? Leidy, Proc. Acad. Nat. Sci. of Philadelphia, vol. v, p. 321. Iconography. The original figures of P. repens a, are those of Schäffer, Eichhorn, Vaucher, Raspail, Carus, Johnston, Brit. Zooph. 1st edit., Johnston, Brit. Zooph. 2d edit., Van Beneden and Dalyell. 1755. Federbusch-polyp. (Original figures.) Variation B. Rösel, Insect. Belustig. Supp., p. 417, tab. 73, 71, 75. 1766. La première sorte de Polypes à Bouquet. Ledermuller, Amus. Micros. 2me cinq., p. 91, tab. 87. (Figures imperfect copies from Rösel.) 1766. Tubularia gelatinosa. Pallas, Elenchus Zooph., p. 85. 1777. Tubularia campanulata. Blumenbach, Handbuch der Naturgeschichte. 1789. Tubularia campanulata. Gmelin, Linn. Syst. Nat., 3834. 1806. Tubularia reptans. Turton, Linn. Syst. Nat., vol. iv, p. 669. 1816. Plumatella campanulata. Lamarck, Ann. sans Vert., 1st edit., vol. ii, p. 108. 1816. Naisa campanulata. Lamouroux, Hist. des Pol. flex., p. 221. 1820. Plumatella campanulata. Schweigger, Handbuch der Naturg., § 76. 1824. Naisa campanulata. Deslongchamps, Encyc. Méth., Zooph., p. 562. 1826. Plumatella campanulata. 1834. Plumatella campanulata. Blainville, Dict. Sc. Nat., vol. xlii, p. 12. Risso, Hist. Nat. de l'Europe Méridion., vol. v, Blainville, Actinologie, p. 490, pl. 85, fig. 6. (Figure copied from Rösel.) 1835. Lophopus campanulatus? Dumortier, Bull. Ac. Brux., p. 424. 1836. Plumatella campanulata. Lamarck, Ann. sans Vert., 2d edit., vol. ii, p. 123. 1837. Plumatella campanulata. Gervais, Ann. Sc. Nat., 2d series, tom. vii, p. 78. 13 Pa prische Scothek 1839. Plumatella campanulata. Gervais, Ann. Franç. et Etrang. d'Anat., tom. iii, p. 134. 1848. Plumatella repens, second variation. Allman, Rep. Brit. Assoc., Trans. of Sect., p. 74. Iconography.-The only original figure of this variation is that of Rösel. HABITAT. In lakes and ponds, and in rivulets of moderate rapidity, attached to the under surface of stones, and to the stems of aquatic plants, and under side of floating leaves, avoiding the light. LOCALITIES.-British: Generally distributed throughout England and Ireland, in some places very abundant. In Scotland it occurs as far north as the Orkneys, whence I have obtained specimens from Lieutenant Thomas, who collected them there in Bea Loch, Sanda; it is probably generally distributed through Scotland, having been met with there in various localities by Dr. Fleming, Sir J. G. Dalyell, and myself. Foreign: Among continental localities, may be mentioned Lake of Lucerne, Lago di Como, in both of which I obtained it during the summer of 1854; the Alpine lakes, Lac Seculejo and Lac d'Aul in the Pyrenees, where I obtained it in the autumn of 1856; in the former at an elevation of 4590 feet, and in the latter at about 6500 feet above the level of the sea. It has been met with also in other parts of France and Italy, as well as in Belgium, Germany, Prussia, Sweden, and Denmark, as recorded by Raspail, Van Beneden, Dumortier, Rösel, Schäffer, Linnæus, Müller, Risso, and other continental naturalists. If Plumatella repens be identical with P. nitida, Leidy, (see below, p. 109,) we will have then, on the authority of Dr. Leidy, an American locality (Pennsylvania) to add to the above. Plumatella repens is a very elegant Polyzoon; the orifices for the egress of the polypides terminate in short, free, tubular ramuli formed by the continuation of the cells, and placed at intervals along the main branches, generally singly, but sometimes in groups of two, three, or even more. The quantity of earthy matter deposited in the ectocyst is small, and this tunic is generally more pellucid than we find it in most other species of the genus; it varies, however, in this respect, according to age and locality of growth, and is for the most part of a brown, or tawny colour, except in the immediate vicinity of the orifices, where it always becomes colourless and transparent; through this transparent portion, the endocyst is visible, and may be here generally seen, dotted with minute, opaque, white spots. We should be careful not to lose sight of the existence of two distinct variations in this species, since a want of the proper recognition of their true significance has given rise, as we have already seen, to a mass of confusion in the synonyms of P. repens, such as, perhaps, can scarcely be paralleled in the literature of Zoology. In the first of these variations, (var. a,) which must be viewed as the normal and typical condition, the animal may be seen attaching itself to flat surfaces, as the under side of stones, and of the floating leaves of the water lily and other aquatic plants. In this condition it is closely adherent throughout its entire length to the surface on which it is developed, and forms elegant dendritic, or confervoid growths, radiating from a common centre. In the second, (var. ß,) it will be found fixed to surfaces of small extent, as thin submerged stems, straws, &c., and as it continues to increase in size, the branches having no extensive surface of attachment, soon become free, and a more or less entangled bushy mass will be produced. These two variations are quite accidental, and altogether the result of external agencies influencing the growth of the species; indeed, the very same specimen will often exhibit both at the same time, continuing closely adherent to the stone or other object to which it happens to be attached, as long as this affords it sufficient surface for adhesion, but becoming free, and assuming the form of the second variation as soon as, in the progress of extension, it arrives at the margin of the sustaining body. In some specimens of P. repens the cells are short, and the orifices, consequently approximated to one another, are placed at slight intervals along the branches, and give a sort of moniliform appearance to the cœnocium; in others, again, the cells are long, and the orifices distant, and this condition chiefly occurs in the free variation where, the elongation of the cells not being restrained by adherence to a fixed surface, the orifices become widely separated from one another, and the moniliform character, so marked in the former condition, is nearly lost. It is in the latter form that the transverse septa are most apparent, indeed, I have met with specimens of the free variation of this species in which well-formed septa occurred between almost every cell, while the elongated claviform figure of the cells increased the resemblance to Paludicella, and even rendered the specimen liable, at first sight, to he mistaken for a large form of the latter Polyzoon. P. repens is a light-shunning animal, and will be found only on the under side of stones, or in such other situations as are not exposed to the direct influence of daylight. The polypides are timid, generally withdrawing on the least disturbance, and not again venturing to display themselves till all is once more perfectly quiet. It often acquires a considerable size. I have met with luxuriant specimens of the adherent variation radiating over a space of upwards of twelve square inches on the surface of a flat stone, and specimens of the free variation have occurred to me with the branches more than three inches in length. In Ireland, P. repens is the most abundant and widely distributed of the fresh-water Polyzoa. It occurs in greatest perfection during summer and autumn. Specific character.-Conocium adherent, creeping; cells cylindrical, narrow, destitute of furrow and keel. Statoblasts elongated. SYNONYM.-1848. Plumatella repens. Van Beneden, Recherches sur les Bryoz., fluv. de Belg. p. 21, pl. 1, figs. 1-4, Mém. de l'Acad. Roy. de Belg., 1848. (Original figures.) Iconography.-Original figures of Van Beneden. HABITAT.-Stagnant waters? adhering to submerged surfaces. LOCALITIES.-British: None. Foreign Brussels and Louvain. Van Beneden. : The present species has been formed for the Plumatella repens, Van Beneden, which, as has already been said, cannot be referred to the original Tubularia repens of Müller, the animal which all naturalists must now take as the model for the identification of the true Plumatella repens. The narrow, cylindrical tubes and elongated statoblasts of P. stricta approach it to P. emarginata, from which, however, it is separated by the absence of a furrow. "We have never," says M. Van Beneden, in his account of this species, "seen the polypary assume that fungoid aspect which is peculiar to the adult Alcyonella. The tubes remain always separated and even considerably elongated from one another. The parent branches lie prostrate upon the surface of the leaves to which they are attache d, but new buds often rise from them at a right angle. "The polypary has often a yellow tint; its walls are less opaque than in the other species" (P. campanulata, Van Ben.) |