Ch. I.] MAEINE ANIMALS AT ADEN. 9 



But time, and the unwonted and intense heat, would not 

 permit of more than a cursory -view of those great works, the 

 water tanks, or of the curious scenes of Eastern life which 

 are to, be viewed in the great market-place and bazaar ; and 

 having taken our glimpse we returned as we had come. 



Having a short time at my disposal before rejoining the 

 vessel, I went down to the beach, where, although the water 

 was rather high, I met with some matters of interest. Under 

 the stones on which were many largish Chitons, were nu- 

 merous grape-like eggs of the cuttle-fish (Sepia), each egg 

 containing a small well-developed cuttle, which, when de- 

 tached, at once moved actively away, and discharged ink from 

 its ink-bag. I was fortunate in finding, also, under a stone, 

 three specimens of a beautiful nudibranch, or mariae slug, 

 which I kept alive for some days for the admiration of some 

 intelligent fellow-passengers, who expressed their astonish- 

 ment that such brilliantly-coloured and graceful creatures 

 should exist, and many were the questions as to how I had 

 found them. They were of the genus BomeUa, and probably 

 Bornella digitata of Adams, a rare species, which had only 

 previously been met with in the Straits of Sunda by Mr. Adams 

 (in H.M.S. " Samarang"), two or three specimens, and the 

 same number on the Madras coast. Delicately marbled with 

 vermilion streaks, they swam freely in the water by a lateral 

 twisting movement of the body, waving at the same time 

 their singularly complex and elegant tufts in a most striking 

 and graceful manner. Vain, however, were all my attempts 

 to depict these nudibranchs in a satisfactory manner, for 

 the conditions on board a mail-steamer are by no means 

 favourable for such studies. I therefore placed them in 

 glycerine, which has a wonderful power of retaining the 

 bright colours, transparency, and delicate outline of some of 



