4-34 PERCY SLADEN TRUST EXPEDITION. 



stomach, which is not large, but except at its hinder end free from the liver. Being 

 white, it is clearly distinguished from the liver by its colour. The intestine is large and 

 broad, and describes a wide bend in front of the liver. This latter is greenish, but most 

 parts of it are covered by the yellowish hermaphrodite gland. The surface is deeply 

 channelled. The ampulla of the hermaphrodite gland is long and coUed. The spermato- 

 theca is greyish ; the spermatocyst yellow. The vas deferens is long and coiled. The 

 albumen and mucus glands form a small compact mass ; the accessory gland described 

 liy Bergh was not found. 



It is with some doubt that I register this form as a new species, though it in any case 

 represents a well-marked colour-variety. It is very unlike the original specimens of 

 M. sinuata (^ nobilis) to look at, but when the points of difference are analysed they are 

 found to concern chiefly the colour and the size of the lobes and tubercles. The following 

 divergences in structure may also be noticed : — 



(1) In M. sinuata the frontal veil is trifld and (in the specimens I have seen) narrow. 



In M. niagnifica it is broad, semicircular, and entire. 



(2) In 31. niagnifica the radula is much larger, though the animal is smaller. 



(3) In 31. sinuata the stomach is surrounded by the liver ; in 31. magnifica it lies 



almost entirely outside it. 



These differences, taken in conjunction with the remarkable coloration, would no doubt 

 be sufficient to constitute a species, provided they prove to be constant. Pending the 

 examination of further material, the forms may be recognized as sejjarate. 



As far as can be judged from an examination of the original specimens, the plates of 

 Miamira nobilis in Semper's ' Reisen ' and the ' Journal of the Godeffroy Museum ' are 

 very misleading. Van Hasselt's drawing, reproduced in Bergh 's 'Notes from the Ley den 

 Museum,' is better, 



22. Trevelyana alba, Bergh. 



) Bergh, Mai. Uuters. in Semper's Reisen, Heft xi. p. 443. 



One specimen, from Cargados Carajos, reef. It is stout, nearly cylindrical in the 

 front and middle parts, but tapering towards the tail. The length is 385 mm., the 

 breadth 15 mm., the height 16 mm. The colour is whitish, with traces of yellow here 

 and there in the creases. The branchiae are 14, and of moderate size. They ai'e set in 

 a complete circle and are mostly bipinnate. On the tail behind them are four rather 

 large low tubercles. 



There is no labial armature. The radula is in a rather confused condition, but its 

 formula seems to be about 30 X 35 . . 35. The hermaphrodite gland consists of two 

 separate roughly spherical portions. 



Though this species is nearly allied to T. ceylonica, it is probably distinct. I have 

 had an opportunity of examining several specimens of the latter from Ceylon, and find 

 them all characterized externally by their large feathery branchise, measuring 8-9 mm. 

 in an animal only 30 mm. long ; whereas in T. alba the branchiae are of moderate size. 

 Further, T. ceylonica shows differences in the radula and the hermaphrodite gland. The 



