CONTRIBUTIONS TO THE BRITISH FAUNA. 



The drawing of Bruguiere, referred to above, 

 exhibits a very just representation of the gene- 

 ral appearance of the animal. He has omitted 

 to delineate the small marginal tubercles of the 

 mouth. 



The genus H'mido, as well as n^any of the ge- 

 nera of the class Annelides, is in great confusion. 

 The present species, and ff. muricata, certain- 

 ly differ in habit and external characters from the 

 fresh-water species of leeches, and ought to con- 

 stitute a separate genus. Unless such subdivi- 

 sions of many of the Linnean genera take place, 

 each genus of the Systema ]^atur(Z will assume 

 the rank of an order, and the families will occupy 

 the station of genera. — (Communicated 9th De- 

 cember laop.) 



5. Echinus miUaris, 



Shell whitish, tinged with violet. The avenues 

 of the pores in pairs, dividing the shell into five 

 small, and five large spaces. The pores are placed 

 in pairs, obliquely disposed in three rows. The 

 smaller spaces have a row of protuberances, the 

 seats of primary spines, on each side close to the 

 pores, with the centre nearly smooth, or covered 

 with very minute spines, divided by a zig-zag line 

 down the middle. These spaces do not reach the 

 top or vertex. The larger spaces are divided by 

 a suture from the vertex to the mouth, more dis- 

 tinct than in the smaller spaces, v^ith horizontal 



