Guide to the Crustacea, Arachnida, Onychophora and Myriopoda exhibited in the Department of Zoology, British Museum (Natural History) .. . easily noticeabledifferences are the greater breadth of the abdomen and the largersize of its side-plates in the female than the male. The first pairof swimmerets (which, unlike the other pairs have only one branchin both sexes) are very slender in the female, but are much largerand peculiarly shaped in the male. The second pair have anadditional lobe on the inner side of the endopodite in the openings of the genital ducts can be seen on the first
Guide to the Crustacea, Arachnida, Onychophora and Myriopoda exhibited in the Department of Zoology, British Museum (Natural History) .. . easily noticeabledifferences are the greater breadth of the abdomen and the largersize of its side-plates in the female than the male. The first pairof swimmerets (which, unlike the other pairs have only one branchin both sexes) are very slender in the female, but are much largerand peculiarly shaped in the male. The second pair have anadditional lobe on the inner side of the endopodite in the openings of the genital ducts can be seen on the first segment(coxa) of the last pair of w^alking legs in the male, and on that ofthe last pair but two in the female. Finally, the female has on c 2 20 Guide to Crustacea. Wall-casesNos. 1-3. the under surface of the thorax, between the last two pairs of legs,a curious three-lobed structure wdth a slit-like opening in themiddle, known as the sperm-receptacle. As in most Crustacea, the eggs are carried, after spawning, bythe parent Lobster, and, as in most of the higher Crustacea(Decapoda), they are attached to the swimmerets on the under. Male. Female. Fig. 5. ^lale and Female Lobsters, showing the dilierence in the relative breadthof the abdomen in the two sexes. This figure also illustrates the dis-similarity of the large claws and the fact that the large crushing-clawmay be on either the right or left side of the body. [Wall-Case No. 1.] surface of the abdomen. The female Lobster carrying spawn inthis way is said by fishermen to be in berry. A specimen inthis condition is shown in spirit, and a drawing, in natural colours,is hung in the upper part of the Case. The number of eggs carriedby a single Lobster may vary from about 3,000 to nearly 100,—Like most other Crustacea, the Lobsterwhen hatched from the egg differs considerably in form from the Lobster—Devclopincni, Moulting, 2 I adult animal. An enlarged drawing oi! this stage is hung in Wall-Wall-case No. 2.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectcrustacea, bookyear19
