i68 THE BRITISH NATURE BOOK 



7. THE LOBSTER (Homarus vulgaris). 



Shrimps, prawns, crabs, and lobsters all have five pairs of walking feet, 

 including the large claws, and are therefore grouped asDecapoda (" Ten-footed "), 

 and the student should take the trouble to dissect specimens in order to see 

 their general similarity. All of them, be it remembered, " moult " or cast their 

 skins, retiring to some secluded retreat until the new " shell " has hardened. 

 Whilst, however, the likeness between the lobster and the shrimp is fairly 

 obvious, the crab's similarity is not so plain, the fact being that the crab's 

 tail, instead of stretching out behind him and being a most powerful weapon, 

 is permanently bent underneath, and fixed close to the under surface. 



The lobster, as is well known, is black until it is boiled. Its claws are in- 

 variably of odd sizes, the larger one being used as a weapon for fighting, the 

 smaller as a hand with which to hold on firmly to the weeds or rocks at the 

 sea bottom. The tail is used as a powerful oar, the animal " doubling it up," so 

 to speak, beneath him with such a powerful stroke and with the plates of the tail 

 outspread that he can shoot a distance of thirty or forty feet with extraordinary 

 swiftness. When moving forward the lobster makes use of the five pairs of 

 swimming legs underneath the tail, and it is to these " swimmerets " that the 

 female glues her eggs. They may vary in number from 2,000 to 12,000, and 

 are thus carried for several months, hatching in June and July. There is one 

 other species frequently taken on our coasts, known as the Norway Lobster 

 (Nephrops norvegicus). This has kidney-shaped eyes, whereas those of the 

 Common Lobster are round, and it is of a pale flesh colour. The Spiny Lobster 

 (Palinurus vulgaris), with its purplish brown back and red-tinted white legs, 

 is not a true lobster ; nor are the so-called " SPANISH LOBSTER," really the 

 Scaly Squat Lobster (Galathea squamifera), and the Spinous Squat Lobster 

 (Galathea strigosa), both of which may be found under stones below low-water 

 mark, and are identified by the spines and " bayonets " on the back and claws. 



8. CRABS. 



There are many species of crabs round our coasts, of which only a few can 

 be mentioned here ; but so common is this animal that it is worth while to 

 know something of its strange life-history (that of the lobster being very similar). 

 From the egg a strange minute creature emerges called a " Zoe'a," about the 

 size of the top of a small pin, not unlike a spiked helmet, with two large eyes 

 in front of it, and a long, jointed tail behind. This swims by turning somer- 

 saults as a means of progress, and feeds upon almost invisible decaying matter. 

 To a great extent it is upon myriads of these " crab caterpillars," if they may 

 be so called, that the whale feeds. Later on the Zoe'a throws off its skin and 

 changes into a " Megalopa " (in reality the " chrysalis " or " pupa " of the 

 crab caterpillar), so called because of its enormous eyes. It is now not unlike 

 a lobster in shape of course very minute still with tiny claws and a long tail. 



