OCR Text |
Show 250 SIR CHARLES ELIOT ON NUDIBRANCHS [Mar. 17, hypertrophy of organs or parts occurred in one sex only, the parts affected were subjected by the habits of the animal, as known by observation, to special irritation and stimulation. Postscript, added April Ibth.-On March 9th, as the left central rectrix in Cock B seemed to be ceasing to grow, I tried to pull it out, but it broke off at the top of the sheath. The total length from the surface of the skin was 4 feet. The right central rectrix in the same bird on March 16th was 3 ft. 4 in. long and still growing. At present it shows no sign of cessation of growth, and has now been growing for more than a year. The appearance of the two birds at the present date is shown in the two photographs (text-figs. 41, 42, pp. 240, 241). 2. On some Nudibranchs from East Africa and Zanzibar. Part I I .1 By Sir C. E l i o t , K.C.M.G., H.M. Commissioner for the East Africa Protectorate, F.Z.S. [Received Februar}' 20, 1903.] C e r a to p h y l l id ia a f r ic a n a , gen. et sp. nov. One specimen from near Wasin, E. Africa, in 9 fathoms. The living animal was described by Mr. Crossland, who dredged it, as of a light greenish-yellow colour on the upper surface, but with the foot, branchiae, and under side of mantle, white. The back was very hard and smooth, but its most remarkable characteristic was the presence of a number of papillae, consisting of round or pear-shaped bodies set on stalks. The stalks as well as the base and tip of these globes were white, but the middle part was black, owing to a dense aggregation of black spots, which, however, can be seen to be separate under a lens. The globes were quite soft and the stalks flexible ; they shook when the animal was moved, but were not observed to execute any spontaneous movements. The mantle-edge was wavy. The alcoholic specimen is of a uniform pale lemon-yellow, the black bands of the globes being, however, preserved. The breadth across the middle of the back is 1*9 centim. Unfortunately the animal is contracted almost into a circle, but apparently the length, when stretched out, must have been about 2'2 centim. The consistency of the body is like hard wax, and fragments of the mantle, which is ample, could easily be detached with the forceps. The whole dorsal surface is a mass of closely packed spicules. It bears about a hundred of the stalked globes. They are of very varying size ; many are quite minute, but the largest is about 3 millim. high including the stalk, and about 2 millim. across the ball, which is quite soft and can easily be pressed flat. They are distributed over the whole of the back irregularly, and not in any pattern, but are perhaps thickest round the mantle-edge, including the space in front of the rhinophores. Both the 1 For Part I. see P. Z. S. 1902, vol. ii. p. 62. |