. An introduction to zoology, with directions for practical work (invertebrates). 164 INTRODUCTION TO ZOOLOGY chap. August, when each female will produce as many as 160,000 eggs! These are carried by the female on her swimmerets for ten or eleven months, and during this time the trapping of such lobsters (said technically to be "in berry") is for- bidden by law. Short-tailed Decapod Crustacea Crabs are essentially similar in general struc- ture to lobsters and shrimps, the great difference in their appearance being due to the fact that the abdomen. Fig. 98.—A Swimming Crab [Portunv^)
. An introduction to zoology, with directions for practical work (invertebrates). 164 INTRODUCTION TO ZOOLOGY chap. August, when each female will produce as many as 160,000 eggs! These are carried by the female on her swimmerets for ten or eleven months, and during this time the trapping of such lobsters (said technically to be "in berry") is for- bidden by law. Short-tailed Decapod Crustacea Crabs are essentially similar in general struc- ture to lobsters and shrimps, the great difference in their appearance being due to the fact that the abdomen. Fig. 98.—A Swimming Crab [Portunv^). (Seen from below.) is permanently bent right under the thorax, so that it can only be seen from below (Fig. 98). Moreover, the carapace is very thick and strong, and is widened laterally, so that in most forms its width is greater than its length. The antennae which project forward are relatively small, and the mouth- parts are covered by the broad, flat, third " jaw feet" (maxilli- pedes); the " walking legs" are very strong, and the first pair bear very large powerful chelae or pincers. In the Edible Crab (Oancer) and in the Common Shore Crab (Carcinus), the large legs are adapted only for walking, and the crabs move by scuttling sideways at a good pace over the ground. In the Swimming Crab (Portunus), shown in Fig. 98, the last pair of legs is flattened and fringed with _ij. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Lulham, Rosalie Blanche Jermaine. London, Macmillan
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Keywords: ., bookcentury1900, bookdecade1910, bookpublisherlondo, bookyear1913
