ARTHROPOD A 71 



classification of some of these is uncertain. There is usually a cephalo- 

 thorax and an abdomen; in some cases these two regions are fused. 

 There are no antennae in the adult. The cephalothorax bears sessile 

 and usually simple eyes. The first pair of cephalo thoracic appendages 

 are the chelicerae; the second pair are the pedipalpi; posterior to these 

 are four pairs of legs. The respiratory organs are sometimes trachea, 

 sometimes book-lungs, sometimes leaf-like external gills. The sexes 

 are usually separate and there is no metamorphosis. 



Crustacea. The American lobster, Homarus americanus. This is 

 probably the most important of our Crustacea. As a laboratory form 

 it is now rather expensive for large classes, but since the crayfish, Fig. 

 53, is almost an exact anatomical copy of Homarus, on a small scale, 

 it is usually used for dissection purposes. 



The Atlantic Coast of North America is the greatest lobster 

 ground in the world, though the lobster industry of western Europe 

 is also important. The species under discussion is found from Labrador 

 to North Carolina, but it is exceedingly rare toward the southern 

 limit of its range; Maine and Massachusetts are the centre of the lobster 

 industry. The Pilgrims found the Indians using the lobster for food 

 and ever since that time it has been one of our most highly prized 

 sea-foods. It is said the Pilgrims paid their debts in England from the 

 products of their fisheries. 



Like so many of the natural resources of the country, all the natural 

 lobster beds of the Atlantic are now more or less depleted and the 

 price of lobsters has risen accordingly; a lobster that could be bought, 

 a generation ago, for 5 cents will now bring a dollar or more. In 

 Canada alone 100,000,000 lobsters have been caught in a year. The 

 total catch in the United States in 1892 was about 23^ million pounds; 

 in 1905 it was about nJ4 million pounds, which sold for more money 

 than the catch of 1892. 



Some of the older accounts described monster lobsters that were 

 "5 or 6 feet long," this probably meant with the claws extended 

 straight in front of the head, which about doubles the length as now 

 measured from the tip of rostrum to tip of tail. The largest authentic 

 measurements that we have give a length, from rostrum to tail, of 

 2 3/ x 4 inches, and a weight of 34 pounds. As a medium-sized lobster 

 weighs only five or six pounds, it will be seen that this 34-pound speci- 

 men was a monster. The European lobster, Homarus gammarus, 



