1904.] FKOM EAST AFIIJCA AXD ZANZIBAR. 389 



outer side. The second and third are much like the innei-most, 

 but are denticulate on the outer side only. The rest are simply- 

 hamate, of the ordinary shape, and bear about 10 minute denticles. 

 The outei-most are, as usual, irregular, and the denticulations are 

 mainly on the apex. 



4. Chromodoris axxulata. (Plate XXIV. figs. 1-3.) 



Chromodoris amiiilata, Eliot, Abstr. P. Z. S. 1904, No. 4, 

 p. 15, March 8. 



Many specimens found among Zostera oft" the mouth of the 

 Creek at Zanzibar nnd other places at low water dui-ing spring- 

 tides. 



The living animal (PI. XXIV. fig. 3) was very soft, with an ample 

 undulated mantle-mai'gin. A lai'ge specimen when in an extended 

 condition was 55 mm. long and 15 wide, but when contracted the 

 same individual was 45 mm. long and 25 wide. The upper surface 

 was of a somewhat tiunslucent white, studded with yellow spots. 

 Round the margin was a border of deep purple, and two rings of 

 the same colour were so placed as just to include the rhinophores 

 anterioi-lyand the branchiae posteriorly within their I'espective areas. 

 The underside was white, with yellow spots on the tail and the sides 

 of the foot. The rhinophores were deep purple, and so long that 

 they were i-ai-ely wholly reti'acted. The branchiae were white, 

 with a deep purple stripe down both the inner and outer edge, and 

 were kept waving from side to side. The animals were found iii 

 conspicuous positions, and made no attempt to hide themselves 

 among the Zostera weed. 



By a somewhat unusual change, which deserves to be noticed as 

 showing how preserving-fluids may alter colour, the alcoholic 

 specimens have become of a reddish purple with white spots, the 

 border and rings having disappeared * and apparently di3"used their 

 pigment over the whole svirface. Fortunately the notes on the 

 living animal were very full, and there appears to be no doubt 

 that the specimens are the same despite theii- ti-ansformation. The 

 body is very soft and the skin peii'ectly smooth. The mantle is 

 ample, the free edge measuiing 7 mm, over the head and 6 at the 

 side in a specimen where the visceral mass is 10 mm, broad. The 

 openings of the i-hinophores and branchite are slightly raised in 

 some, but not in all the specimens, and vary in size. They are no 

 doubt capable of contiuction and expansion in life. The biunchia^ 

 (PI, XXIV, fig. 2) vary in number from 9 to 16 according as an 

 inner row is present or not, but on an average the smaller number 

 is more frequent in this species than in Chr. reticulata^ sykesi, and 

 cavce. The foot is nari-ow and rounded, grooved in fi'ont but not 

 notched. Two small folds pass upwards from the foot, uniting it 

 with the sides of the head and with the mantle. The tenta.c]es 

 are small and placed at the lower angles of the mouth. The labial 



* [Their dark purplc-bluc became a! uioit at once a light red, which tlisappearcil 

 graduallv.— C. C] 



[in 



