. The Cambridge natural history. Zoology. 194 CRUSTACEA—EUCARIDA-—DECAPODA the place of our common Carcinus maenas, which is not found Among Fig. 134.—Dorsal view of Pacliygrcqysus marmoratu!^, X J. (From an original drawing prepared for Professor Weldon.) the land genera are Ocypoda, Gelasi- mus, and Gecar- cinus of tropical lagoons and coastal swamps. Ocyjpoda often occurs in vast crowds in these regions, and digs burrows in the sand. Gelasinius (Fig. 13 5) is remarkable for the enormous size of one of the chelipedes, generally the right, in the male, which may actually exceed in siz
. The Cambridge natural history. Zoology. 194 CRUSTACEA—EUCARIDA-—DECAPODA the place of our common Carcinus maenas, which is not found Among Fig. 134.—Dorsal view of Pacliygrcqysus marmoratu!^, X J. (From an original drawing prepared for Professor Weldon.) the land genera are Ocypoda, Gelasi- mus, and Gecar- cinus of tropical lagoons and coastal swamps. Ocyjpoda often occurs in vast crowds in these regions, and digs burrows in the sand. Gelasinius (Fig. 13 5) is remarkable for the enormous size of one of the chelipedes, generally the right, in the male, which may actually exceed in size the rest of the body. It is not known for what purpose this organ serves in the various species. In Gelasimus it is supposed that the male stops up the mouth of the burrow with it when he and the female are safely inside. It is also used as a weapon in sexual combats with other males; but Alcock, from observations made in the Indian Ocean, be- lieves that the males use it for exciting the admiration of the females in courtship, as the huge chela is bright red in colour, and the males brandish it about before the females as if displaying its florid beauty. The species of Ocypoda are exclusively terrestrial, and cannot live for a day in water. The gills have entirely disappeared, and the branchial chambers are converted into air-breathing lungs with highly vascular walls, the entrances into which are situated as round holes between the bases of the third and fourth pairs of walking legs. As their name implies, they can run with. 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 Harmer, S. F. (Sidney Frederic), Sir, 1862- ed; Shipley, A. E. (Arthur Everett), Sir, 1861-1927. ed. [London, Macmillan and Co. , Limited; New York, The Macmillan Company
Size: 1850px × 1350px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
