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Show 1906.] OF SOUTHERN INDIA AND CEYLON. 689 Several of these twenty-seven species are probably mere colour varieties. It is, for instance, clear that in both the tropical Pacific and tropical Atlantic there is found a greenish Elysia in which one or more coloured borders and spots of various colours may be present or absent. More distinct are the forms with a coloration offering vivid contrasts and often brilliant, such as E. ccerulea, E. picta, and E. haingsisianci. Other good characters may perhaps be found in the shape and denticulation of the teeth, and in the conformation of the wings, tentacles, and pericardial prominence. E l y s ia g r a n d ifo l ia * Kelaart. (Plate XLYI. fig. 4.) (Kelaart, 1. c. II. p. 493.) Two specimens preserved with the rest of Kelaart's molluscs are probably referable to this form, but have no label. They are of a uniform yellowish grey, much contorted, and so decayed and fragile that it is hardly possible to unroll them without breaking them. They are about 30 mm. long and 20 mm. broad. The wings are ample and the tail long and pointed. The rhinophores are well developed and auriculate. The mouth is ventral. The sole is not in any way marked off from the under side of the wings. Though the specimens are in such bad condition, it seems clear in both of them that the pericardial prominence is not a simple round lump, but that the pericardium or some accessory organ is prolonged posteriorly for about 10 mm. The projection is not even, but constricted several times. From either side of it spring about seven main trunks of prominent vein-like reticulations. Each is subdivided many times and the whole upper surface of wings is covered with an elaborate raised network. The radula consists of 8 teeth in the ascending series, 12 in the descending, and about 20 in the heap. They are of the form usual in the genus, hollowed in the back and rather straight in outline. Under the highest power the lower edge appears minutely serrulate, but this serrulation is not visible under lower powers. Kelaart's figure agrees fairly well with the specimens, but the head, as drawn, is rather small. The coloration resembles Bergh's figure of Elysia ornata (Siboga, pi. ii. fig. 20) and my figures of Elysia marginata (Proc. Zool. Soc. 1904, ii. pi. xvi. figs. 7, 8), but neither of these has the pointed tail and the elongate pericardial prominence. The latter feature appears in E. dubia Eliot (Proc. Zool. Soc. 1. c. p. 297). E l y s ia c.e r u l e a Kelaart. (Plate XLIII. fig. 7.) (Kelaart, 1. c. II. p. 493. Cf. Bergh on Elysia ? lineolata, in Siboga-Expeditie, Opisthobranchia, pp. 85-87.) This can hardly be anything but the Elysia lineolata of BeroO- h7 * By an error Bergh has registered this animal in his lists as E.grandiflora but Kelaart calls it grandifolia both in MS. and in print. 46* |