153 



MOILTJSCA. 



"Oh! what an endlcsse work have I in hand, 

 To count the sea's abundant progeny ! 

 Whose fruitful seede farre passeth those in land, 

 And also those which wonne in the azure sky; 

 And m ucli more eath to tell the starres on by 

 Albe they endlesse seeme in estimation; 

 Then to recount the sea's posterity, 

 So fertile be the flouds in generation, 

 So huge their numbers, and so numberlesse their nation." 



SPENSER'S FAEUY QUKKNE, Book iv. canto xii. 



Fig. 147. LYMHEUS STAGNALIS. 



THE soft -bodied animals, to which the term "Mollusca" is 

 applied, constitute another of the primary groups of the animal 

 kingdom. In them we see no longer the jointed or articulated 

 structure characteristic of the Crustacea and insects. The 

 body, as the very name of the group implies, is soft, and it is 

 devoid of the jointed legs, which, in some of the preceding- 

 tribes, were applied to such diversified uses. The nervous 

 system is also different, being unsymmetrical; it consists of a 

 ring surrounding the gullet, with one or two ganglions or 

 knots of nervous matter connected with similar masses in 

 other parts of the body. "The blood is colourless, or not 

 red,"* and the respiratory organ or gill, which is never 



* Owen, page 13. 



