192 THE POPULAR SCIENCE MONTHLY. 



iugs were of the same individual — it was simply the childhood, youth, 

 and manhood, of one person. Many years ago the naturalist described 

 a little crustacean which was noticed swimming gayly and briskly in 

 the sea. It was a pert little thing, rather pretty, and very quaint. It 

 had large, full eyes. In fact, they were enormously so for such a di- 

 minutive being. Between these great optics, projecting downward 

 like the coulter of a plough, was a long, sharp spine. On each side of 

 the body was a much shorter spine, and over this short spine on each 

 side, and high up near the back, were two fan-like structures, almost 

 suggestive of wings, as with these four it really sped its way through 

 the water. Between these, and from its back, rose by far the longest 

 spine, almost equal to its entire self in length. It was immensely 

 long, yet delicate and sharp. This outre little thing received the 

 name Zoea pelagica. In rank it was considered an entomostracan, the 

 lowest, the nqiy^ pariah of the race. The naturalists also found an- 

 other little crustacean, something larger, and not so testy-looking 

 either. It had not the formidable spines, but it had feet on the ab- 

 domen, which Zoe had not. There were also other groat differences. 

 It had, however, like Zoe, large eyes ; and so the systematists named 

 it Megalops. Well, just here the joke comes in, if indeed we may 

 suppose a joke possible in so serious a science as zoology, especially 

 in the department of the crabs. But the fact was that Zoe, and Me- 

 galops, and Cancer, were but the childhood, youth, and adult stages 

 of the same individual, namely, the crab. Now, as Cancer by common 

 consent belongs rightly to the highest crustacean rank — that is, the 

 decapods — so do Zoea and Megalops. 



The common edible crab of Europe has for its scientific name 



Fig. 1. 



Common Crab of Europe, 



Cancer pagurus. It is a much more massive crab than our edible 

 crabs; individuals have been known to weigh twelve pounds each! 

 Let the reader compare the cut of the European crab. Fig. 1, with that 



