BIOLOGY FOR YOUNG BEGINNERS. 



583 



and paddles the lobster owns (Fig. 15). He has six pairs attached 

 to the head, eight pair to the breast (thorax), and six pairs to the body 

 (abdomen) ; in all, twenty pairs, and very few of these appendages 

 are alike. 



NAMES OF LOBSTER S APPENDAGES. 



Head appendages. 



Thoracic appendages. . - 



Abdominal appendages. 



I pair. 



II '' . 



III " . 



IV " . 

 V " . 



VI " . 



VII " . 



VIII " . 



IX " . 



X " 



XI " . 



XII " . 



XIII " . 



XIV " . 



XV " . 



XVI " . 



XVII " . 



XVIII " . 



XIX " . 



XX " . 



Eye-stalks. 



Antennules, or small feelers. 

 Antennae, or great feelers. 

 Mandibles, or true jaws. 



Maxillae, or little jaws. .. 



I Maxilla?, or little jaws \ f irst , P* ir ' 



) J ( Second " 



) I First 



> Maxillipedes, or foot-jaws. . < Second " 



) / Third 



Chelae, or pincers. 

 1 fXI. and XII., 



[Ambulatory limbs, or walk- J ^tt? 111 a ' 



f in S- k - s I XIV.; with- 



J [_ out pincers. 



Swimme7-ets, or little swimmers. 



You now have a pretty good idea of the exo-skeleton, or hard out- 

 side part of the lobster, and we shall look next at the soft parts inside 

 (Fig. 22). The mouth seems a very good place to begin at, and you 

 will find it between the mandibles, or jaws. In front of it is a lip, 

 shaped like an escutcheon, and is called the labrum, which means lip. 

 At the back of the mouth is another lip, the metastoma, meaning be- 

 yond the mouth, and this is looked upon as the lower lip. The mouth, 

 as in the mussel, opens into a gullet, or oesophagus. This meat-pipe 

 opens into a four-cornered box (Fig. 22) the stomach which is very 

 curiously made. 



Near the centre of the box the walls come almost together, divid- 

 ing it into two parts : the front part is the larger, and it is called the 

 cardiac end, because in the human body the first part of the stomach 

 points toward the heart, but you see, in the lobster, it points away 

 from the heart. It contains three strong, colored teeth, fastened to a 

 T-shaped frame (Fig. 23), and worked by muscles which are fastened 

 to the inside of the breastplate (carapace). These teeth meet in the 

 middle of the stomach, and form a powerful grind ing-machine, which 

 crushes the food like the stones in a mill (Fig. 24). Sometimes, when 

 you find the empty shell of a lobster on the sea-shore, you can see a 

 perfect mould of the old mill " the mill-wheel gone to decay." How 

 the lobster sets out of his shell, and how he turns the mill out of his 

 stomach, we shall study after a while. The small back part of the 



