THE STKAIT OF MAGELLAN. 23 



the Cape de Verde group are the genera Oxycara and 

 Trichosternum, belonging to the Heteromous section of the 

 order. In the course of our walk we noticed some fine 

 examples of wind-blown ridges of sand, exactly counter- 

 feiting ripple-mark. After a time, we descended to the 

 beach, and spent an hour or two in search of marine animals. 

 We found the shore at high-water mark thickly strewn with 

 dead shells, among which the genera Conus, Purpura, 

 Cyprcea, Spoiulylus, Area, and Venus, predominated, as well 

 as numerous examples of water-worn corals, chiefly belonging 

 to a species of Astrcea. The state of the tide fortunately 

 permitted us to investigate the pools in a flat reef of rocks 

 extending for some distance along the bay ; and in these we 

 met with a variety of live animals, the collection of which 

 required to be conducted with caution, as a heavy surf broke 

 over the rocks at short intervals. A curious little blennioid 

 fish, the Clinus nuehipinnis, darted rapidly about the pools 

 in numbers, and required some dexterity to capture ; and a 

 small Octopus, probably of the same species as that of 

 which Mr. Darwin has given such a lively description in 

 his account of his visit to St. Jago, caused us much amuse- 

 ment by the agility of its movements — swimming through 

 the water with great rapidity, tail foremost, occasionally dis- 

 charging the contents of its ink-bag to screen itself from 

 observation, and, when placed on the rock, scrambling along 

 at a great rate, by means of its arms, in such a fashion as to 

 remind us of a frog. A large Aplysia (A. dactylomela), also 

 mentioned by Mr. Darwin, was not uncommon, and dis- 

 charged a brightly-coloured fluid, varying from purple to 

 carmine, when handled. Among the other molluscs found 

 by us were a Conus, a small Mitra, many specimens of 

 Purpura neritoides, and examples of P. hcemastoma, Littorina 



