118 PERCY SLADEN TKUST EXPEDITION. 



larger groups each row contains eight cerata ; in the smaller the number is less. Each 

 group is set on a ridge or common base, which is about 4 mm. long and 2 mm. high in 

 the largest groups, and is curved or oblique, extending a little way beyond the side of 

 the body. The largest cerata are 8 mm. long ; the outer ones are minute. 



The radula is rmiseriate and consists of about 70 very broad plates, which ai-e 

 almost pectinate as in Aeolidla, though the denticles are not very numerous, being 

 only 8 or 9 on either side of the central cusp, which is distinct though not very 

 prominent. The posterior portion of each tooth is expanded on either side into a sort 

 of accessory plate (see PI. 25. fig. 13). 



The jaws bear a single row of distinct but irregular denticles, often pointed, but 

 sometimes blunt or square at the tips. 



In order to preserve the specimen, which though bent is in good condition, and has 

 kept its colours unusually fresh and distinct, no further dissection was made. 



This animal bears a strong superficial resemblance to Kelaart's figure of Eolis bicolor 

 (reproduced in Proc. Zool. Soc. 1906, pi. xlv. fig. 4), which is probably identical with 

 the SamJa annuligera described by Bergh in Schauinsland's ' Reise nach der Pacific : Die 

 Opisthobranchier,' pp. 236-239. But even externally there is some difference, since the 

 number of cerata in each group is greater in this species and the common base is larger. 

 Also the radula consists of a single series of about 70 teeth, whereas Samla has a short 

 radula of 20 rows, each containing three teeth. 



The specimen must be referred to Pterueolklia, but is distinguished from Ft. semperi, 

 a common Pacific form, not only in colour, but also by the length of the radula and the 

 shape of the teeth. 



3. Elysia punctata (Kelaart). 



See Eliot, in Proc. Zool. Soc. 1906, p. 690. 

 One specimen labelled Coetivy. It is rolled up into a ball as preserved, but would be 

 about 30 mm. long and 15 mm. broad if straightened. The integuments are much 

 decayed, but what remains of the skin is greenish wdth black dots, which are especially 

 thick on the rhinophores and just in front of the pericardium. The teeth of the radula 

 are not denticulate, and number seven in the ascending portion, six in the descending, 

 and about a dozen in the heap. 



4. Marionia cyanobranchiata (Riippell & Leuckart). 

 See Eliot, in Jouru. Linn. Soc, Zool. vol. xxxi. 1908, pp. 120-2. 



Two specimens from Egmont reef. As preserved they are of a light primrose-yellow, 

 with whitish tubercles, which seem to rise in the meshes of a reticulate pattern. But 

 these markings have become vo-y faint. On some of the branchiae are traces of bluish- 

 green colour. The measurements as preserved are about 25 by 20 mm., but the 

 animals were no doubt considerably longer and thinner when alive. 



The oral veil bears eight simple appendages besides a pair of tentacles. The branchiae 

 are nine on each side, arborescent and very ample, so that they entirely hide the 



