70 



ZOOLOOT. 



When Y^- mm. (Jj inch) in diameter it becomes fixed to a 

 rock, and at the end of a year is capable of breeding. Oy- 



FlG. 78. — A, Venus mercenaria, quohog, natural size, with the foot and siphons; 

 B, Macira {Mulinia) lateralis, natural size. 



Bters get their full growth by the second or third year. 

 They breed from July to September. 



Fla. 79.— The Ship-worm, natural size. t. siphons; p, pallets; c, collar; s, shell; 



/, foot. 



The mussel (Fig. 77) has a small foot, with a gland for 

 secreting a bundle of threads, the bynstis, by means of 



