THE BAY OF BISCAY. 1G9 



laminated rocks are so constantly penetrated by the 

 waves to their very innermost fissures and indenta- 

 tions that they cannot nourish a very numerous 

 population ; but as the animals which live in these 

 recesses belong to a warmer sea than the Channel, 

 they were to a certain extent new to me, and on this 

 account they were the more highly valued. It must, 

 moreover, be remembered that in the present state 

 of science no real interest can attach itself to super- 

 ficial studies embracing a very large number of 

 animals. A single species thoroughly and systema- 

 tically studied will teach more than a hundred that 

 have been cursorily examined. The great matter, 

 however, is to make a judicious choice, and in this 

 respect I was very fortunately situated. At Guettary I 

 found an abundance of those Polyophthalmians which 

 I h#d already studied in Sicily together with the same 

 Hermellas which I had casually seen at Granville. 

 These two types were represented here by species 

 which differed from those with which I was already 

 acquainted. I lost no time in testing my past re- 

 searches by a new and severe revision, while at the 

 same time I entered upon fresh inquiries, and the 

 results of these investigations, of which I shall en- 

 deavour to give some idea, fully recompense me for 

 all my labours. 



On these coasts, which are so violently beaten by 

 the waves, we often observe small hillocks of sand 

 pierced by an infinite number of minute openings 

 half covered by a thin projecting margin. These 

 mounds are either found behind some large rock or 

 in some deep fissure, although occasionally they are 



