1904.] FROM EAST AFRICA AXD ZANZIBAR. 389 



outer side. The second and third are much like the innermost, 

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

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

 The outermost are, as usual, irregular, and the denticulations are 

 mainly on the apex. 



4. Chromodoris annulata. (Plate XXIV, figs. 1-3.) 



Chromocloris annulata, Eliot, Abstr. P. Z. S. 1904, JSTo. 4, 

 p. 15, March 8. 



Many specimens found niiiong Zostera ofi' the mouth of the 

 Creek at Zanzibar and otliei- places at low water during spring- 

 tides. 



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

 undulated mantle-margin. 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 translucent 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 rhinophoi-es 

 anteriorly and the branchise posteriorly within their respective 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 rarely wholly retracted. The bi'anchise 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 in 

 conspicuoiis 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 diffused their 

 pigment over the whole surface. Fortunately the notes on the 

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

 that the specimens ai'e the same despite their transformation. The 

 body is very soft and the skin perfectly smooth. The mantle is 

 ample, the free edge measuring 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 rhinophores and branchiee 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 branchiae 

 (PI. XXIY. 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, syhesi, and 

 cavcB. The foot is narrow and rounded, grooved in front but not 

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

 with the sides of the head and with the mantle. The tentacles 

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



* [Tlieir dark purple-blue became almost at once a light red, wliicji disappeared 

 gradually.— C. C] 



26* 



