THE EUROPEAN SEAS. 



89 



less distances, Gadus callarius having the farthest 

 range. Of flat fish, the Pleuronectes platessa thrives 

 throughout ; also the P. limandus and P. maximus. 

 Both our Celtic sand-eels occur, and a pipe-fish or 

 two. The mackerel rarely enters this sea; the nine- 

 spined stickleback is common, and a fresh-water 

 species descends into the sea. Gurnards are rare, 

 gobies and bull-heads common. The gunnel, the 

 viviparous blenny, the sea lamprey, and the stur- 

 geon, make up the summary of Baltic fishes. The 

 invertebrate inhabitants of this sea are as few in 

 proportion as the vertebrata. This character of its 

 zoology is strikingly seen when we regard its mol- 

 luscous population. Were the area, in any respect, 

 the centre of a peculiar fauna, we should expect to 

 find indications of a special creation, manifested by 

 the mollusks. Instead of this being the case, once 

 we have passed some way within the Sound, these 

 animals become exceedingly few, whether we regard 

 the number of genera or of species. A single peri- 

 winkle, the Littorina rudis, and its minute ally, the 

 Rissoa (Hydrobia) ulvce, slightly modified, miserably 

 represent the long list of Celtic gasteropoda. A few 

 bivalves, such, as Tellina solidula and tenuis, Donax 

 anatinum, Cardium edule, Mytilus edulis, and Mya 

 arenaria, constitute the Lamellibranchs of this sub- 

 region. Some of these, Tellina solidula for example, 

 become slightly modified through the influence of 

 local conditions, and have been elevated by over- 

 anxious patriots into distinct species, with the dis- 



