EXPLANATION OF THE PLATES. PLATE I. Fig. 1, a, b. Astemma filiformis. a. Nat. size. b. Portion magnified. Fig. 2, a, b. Convoluta paradoxa, magnified. b. Showing the involute margin. Fig. 3. Planaria hirudo, magnified. Figs. 4-6. Pontobdella littoralis. 4. Nat. size. 5. Magnified. 6. An outline figure drawn from an individual which had the genital organs extruded. PLATE II. a. Figs. 1, 1*. Omatoplea gracilis. 1. Nat. size. 1. Anterior portion magnified. Figs. 2, 2*, 2**, 3, 3*. Omatoplea rosea. 2. Nat. size, both figures. 2*. Anterior portion. 2**. Caudal extremity :-both magnified. 3. Var. brunnea, nat. size. 3*. Head magnified. Fig. 4. Tetrastemma varicolor, nat. size. Figs. 5, 5. Omatoplea melanocephala. 5. Nat. size. 5*. Mag nified. Figs. 6, 6*. Omatoplea pulchra. 6. Nat. size. 6*. Anterior portion magnified. PLATE II. b. Figs. 1, 1*, 1**. Borlasia olivacea. 1, 1, 1. Nat. size. 1*. Anterior and middle portions magnified. 1**. Embryo? Figs. 2, 2*. Borlasia octoculata. 2. Nat. size. 2*. Anterior portion magnified. Figs. 3, 3*. Borlasia purpurea. 3. Nat. size. 3*. Head, anterior portion, middle, and tail, magnified. Figs. 4, 5. Astemma rufifrons. 4. Nat. size. 5. Portion of ante rior extremity magnified. Spirorbis minutus, Flem. Edinb. Encycl. vii. 68. Johnston, Ann & Mag. Heterodisca minuta, Flem. Edinb. Phil. Journ. xii. 247. . (a) Falmouth (on stones), W. P. Cocks. In his "Index to the British Annelides," in the Annals and Magazine of Natural History, vol. xvi., 1845, Dr. Johnston has given a list of a good many other species which have been described by various naturalists. As specimens do not exist in the National Collection, we shall merely give here the species as mentioned in the work above quoted. Sp. 8. Spirorbis carinatus. Serpula carinata, Mont. Test. Brit. 502. Spirorbis carinatus, Flem. Edinb. Encycl. vii. 68. Sp. 9. Spirorbis Montagui. Serpula, n. sp., Mont. Test. Brit. 502. Spirorbis Montagui, Flem. Edinb. Phil. Journ. xii. 245. Sp. 10. Spirorbis incurvatus. Serpula incurvata, Turt. Gmel. iv. 609. Spirorbis incurvatus, Flem. Edinb. Phil. Journ. xii. 245. Sp. 11. Spirorbis pervius. Vermiculum pervium, Mont. Test. Brit. 518. Spirorbis pervius, Flem. Edinb. Phil. Journ. xii. 245. Sp. 12. Spirorbis retortus. Serpula retorta, Turt. Gmel. iv. 609. Spirorbis retortus, Flem. Edinb. Phil. Journ. xii. 245. Sp. 13. Spirorbis annulus. Spirorbis annulus, Brown, Illust. pl. 1. f. 44. Sp. 14. Spirorbis heterocliticus. Spirorbis heterocliticus, Brown, Illust. pl. 1. f. 57. Sp. 15. Spirorbis striatulus. Spirorbis striatulus, Brown, Illust. pl. 1. f. 59. Sp. 16. Spirorbis conicus. Spirorbis conicus, Flem. Edinb. Encycl. vii. 68. pl. 205. f. 3. Sp. 17. Spirorbis reversus. Serpula reversa, Mont. Test. Brit. 508. Spirorbis reversus, Flem. Edinb. Encycl. vii. 69. Heterodisca reversa, Flem. Edinb. Phil. Journ. xii. 248. Page 279, Mæa mirabilis, at end of description add (a) Scotland, Dr. Greville. Append. page 304, for Plate II. C. read Plate I. EXPLANATION OF THE PLATES. PLATE I. Fig. 1, a, b. Astemma filiformis. a. Nat. size. b. Portion magnified. Fig. 2, a, b. Convoluta paradoxa, magnified. b. Showing the involute margin. Fig. 3. Planaria hirudo, magnified. Figs. 4-6. Pontobdella littoralis. 4. Nat. size. 5. Magnified. 6. An outline figure drawn from an individual which had the genital organs extruded. PLATE II. a. Figs. 1, 1*. Omatoplea gracilis. 1. Nat. size. 1. Anterior portion magnified. Figs. 2, 2*, 2**, 3, 3*. Omatoplea rosea. 2. Nat. size, both figures. 2*. Anterior portion. 2**. Caudal extremity :-both magnified. 3. Var. brunnea, nat. size. 3*. Head magnified. Fig. 4. Tetrastemma varicolor, nat. size. Figs. 5, 5*. Omatoplea melanocephala. 5. Nat. size. 5. Mag nified. Figs. 6, 6*. Omatoplea pulchra. 6. Nat. size. 6. Anterior portion magnified. PLATE II. b. Figs. 1, 1*, 1**. Borlasia olivacea. 1, 1, 1. Nat. size. 1*. Anterior and middle portions magnified. 1**. Embryo? Figs. 2, 2*. Borlasia octoculata. 2. Nat. size. 2*. Anterior portion magnified. Figs. 3, 3*. Borlasia purpurea. 3. Nat. size. 3*. Head, anterior portion, middle, and tail, magnified. Figs. 4, 5. Astemma rufifrons. 4. Nat. size. rior extremity magnified. 5. Portion of ante PLATE III. Various kinds of bristles connected with the feet, &c., of Annelides (simple bristles), figs. 1-23:-magnified. Fig. 1. A spine (aciculus); generally one or two occur in each fascicle of bristles in each foot. 2. A forcipate spinet. 3, 3*-5. Forked spinets. 6, 7. Setaceous bristles. 8, 9. Ventricose bristles. 10, 11, 13, 14. Lanceolate bristles. 15. ? A seta belonging to Lepidonotus pellucidus. 17-19. Tarsiform bristles from the superior and inferior branches of one of the feet of Lepidonotus pharetratus. 21-23. Spinous bristles. PLATE IV. Various kinds of bristles connected. with the feet, &c., of Annelides:-magnified. Figs. 1-13. Compound bristles, peculiar to the Annelida rapacea. The compound bristles are bristles of which the shaft is broken into two halves by an imperfect sort of joint; the lower portion is the shaft, and the upper the terminal piece. Fig. 1 is a tarsiform compound bristle. Figs. 2, 6 & 12 are falcate compound bristles. Fig. 7 is an acicular compound bristle. Figs. 5 & 6. Two bristles of the ventral branch of Lepidonotus clava. Figs. 14-17 are hooklets of one of the feet (uncini); almost peculiar to the tubicolous Annelides, the Terebellida, Serpulidæ, &c. PLATE V. Lepidonotus semisculptus. Fig. 1. The animal magnified: the line by its side shows the natural size*. 2. The head magnified, under surface. 3. Spine? 7-11. Various bristles, magnified. PLATE VI. Fig. 4 of Plate V. A scale of Lepidonotus semisculptus. Fig. 5 of Figs. 1-5. Pholoë eximia. 1. Animal magnified. 2. A scale; one of the upper twelve. 3. One of the ventral bristles. 4. One of the jaws. 5. One of the dorsal bristles:-all magnified. * Unfortunately, the specimen mentioned by Dr. Johnston is not in the Collection, and though the figure agrees in most respects with his description, it does not tally with it in the number of scales. He describes the animal as possessing 15 pairs, the figure represents 20. A specimen of a Lepidonotus lately received from Guernsey, and now in the Museum Collection, and which I consider as being L. semisculptus, has 20 pairs of scales, and therefore, perhaps, the number 15 may be a misprint not corrected by Dr. Johnston as the MS. went through the press.-W. B. |