1904.] FROM EAST AFRICA AND ZANZIBAR. 89 



various organs are fresh and strong, whereas in other cases they 

 may have dried up or decayed. The verge is armed with numerous 

 small spines of veiy variable shape, simple, bifid and trifid. From 

 the genital mass to the tail extends on each side a long, ramified, 

 almost arborescent gland, distinctly visible through the trans- 

 parent body-wall with which it is united. 



Trevelyana bicolor (?). (Plate lY. figs. 1 a-1 c.) 



[A. & H., Notes on a Coll. of Nud. Moll, made in India, p. 132, 

 pi. xxix. figs. 11, 12.] 



The single specimen, which was captured at Prison Island, 

 Zanzibar, was 20 millimetres long, with a very long nari'ow foot, 

 tapering to a point posteriorly. The whole animal was white, 

 with projecting spots of bright yellow. The tips of the rhino- 

 phores and edges of the gills were also bright yellow. The liver 

 showed through the dorsal integuments as a black mass before 

 and behind the branchiae, and in front of it were seen the yellow 

 reproductive organs. The branchife were simple and leaf-like and 

 shrunk together when touched. 



The preserved specimen is contracted into a spheiical shape, 

 showing no trace of the raised spots or of a mantle-margin. 

 The head-parts are much retracted and distorted, but the anterior 

 margin of the foot seems to have been deeply grooved. The 

 colour is white, but the black liver is still conspicuous. The 

 twelve branchiae are set in a complete cii-cle. 



The radula consists of 26 rows, the widest of which contain 

 24 closely packed teeth. The first lateral is large and hamate and 

 the next much like it. The other teeth are rather stout, of the 

 bradawl shape or slightly curved. In the pharynx were found the 

 remains of a small tectibranch, which, to judge from its radula 

 and stomach-plates, was probably Ati/s. 



I think this form is probably A. & H.'s T. bicolor. Their 

 description was made from the drawing which they reproduce 

 and they saw no specimen. The bicoloration there depicted was 

 probably due to the liver being seen through the integuments, for 

 though the picture certainly suggests a black patch on the skin, 

 it will be seen that this patch occupies exactly the position of the 

 liver, and that it bears yellow spots like the white part. It is 

 also possible that Rlippell and Leuckart's T. impudica is identical 

 with this form. They describe it (Neue wirbellose Thiere des 

 rothen Meers, p. 33) " corpore dilute lacteo ; tentaculis superi- 

 oribus, maculis ocellisque dorsalibus, branchiis pedisque limbo 

 aurantiacis ; dorso tuberculato ; branchiis 1 2 medium dorsi versus 

 sitis ; pallio indistincto." 



Nembrotha B. 



[Bergh, S. E. xi. p. 450, figs., xvii. p. 980, figs. ; id. Beitr. 

 zu einer Monographie der Polyceraden, ii. p. 658, figs., and iii. 

 pp. 164-5.] 



This genus is allied to Trevelyana, but both internally and 

 externally can be readily distinguished from it. The coloration is 



