1904.] FROM EAST AFRICA AXD ZANZIBAR. 395 



discernible. All the teeth which I examined wei-e hamate, with 

 bifid tips, exactly like those of Chr. semperi as figured by Bergh. 



Another specimen captured at Ohuaka, on the East Coast of 

 Zanzibar, seems to belong to the same species, though at first sight 

 is strikingly difiierent from the indiviclual described above, being- 

 larger, stouter, and of anotlier colour. The notes on the living- 

 animal describe it as lemon -yellow, with very deep purple-black 

 stripes ; the gills and rhinophores vermilion ; the foot purplish 

 underneath and at the edges. 



The preserved specimen is pale yellow, with black lines arranged 

 much as already described, including- a horseshoe round the 

 branchiae, but shorter and moi'e numerous. It is 30 mm. long, 

 15 high, and 13 broad. The mantle-edge is a narrow thick ridge, 

 measuring 1"5 mm. at the sides, 2*5 over the head, and 3 over the 

 tail, which is 10 mm. long. The body is high and thick, but the 

 sole of the foot narrow (maximum 3 mm.). The pockets of the 

 rhinophores and bi-anchise are small and very slightly i-aised. 

 The bi-anchia? are ten, set in a complete circle, but the anterior 

 plumes are larger than the posterior. One of the latter is very 

 small and pei'haps merely an ofishoot. The foot is rounded in 

 front, grooved but not notched. The tentacles ai-e retracted and 

 hardly visible. 



The labial armature is yellowish and formed of short thick hooks. 

 The formula of the large and closely- packed but veiy fi-agile radula 

 is about 90 x 75.0.75. The teeth are mostly bifid at the tip atid 

 otherwise smooth. Only the innermost have an accessory denticle 

 on the inner side, and are thus trifid. The outermost are serrulate 

 at the apex. 



These two specimens seem to be merely colour- varieties of a 

 single species which is closely related to Chr. semperi B. Except 

 that the external teeth of the radula bear more numerous and 

 more distinct serrulations, the principal charactei'S appeal- to be 

 identical. But whei-eas Chr. semperi is spotted, the animals here 

 examined are marked with exceptionally clear and nari-ow black 

 lines, which seem engraved on the surface. They must therefore 

 be accorded specific rank, at least provisionally. It is possible 

 that intermediate forms may be discovered, as the variety first 

 described bears some yellow blotches. 



11. Chromodoris scurra B. 



Chromodoris scurra Eliot, Proc. Acad. ISTat. Sci. Philadelphia, 

 Dec. 1899, p. 518. 



[Bergh, S. R. xi. p. 478, and Journal de Mus. Godeftroy, Heft vi. 

 1874.] 



Two specimens from Zanzibar Hai-bour. 



The colours of the living animal are brilKant. Down the centre 

 of the back runs a white line, and on each side of it are borders 

 in the following order : (1) narrow deep red line, (2) broad orange- 

 .yellow band, (3) narrow deep red line, (4) violet band, which 

 broadens out antui'iorly and posteriorly, (5) white border running 



