CRUSTACEA. 155 



an eye, an antenna, or one or more limbs. They surpass 

 most marine animals in their powers of enduring life at a 

 distance from sea-water, and may easily be kept for several 

 weeks in a botanic vasculum. 



The shore-crab is strictly carnivorous and, as already men- 

 tioned, even relishes its fellows. It is a curious feature in 

 its history that it suffers serious annoyance and injury from 

 the young of the common mussel, which plant themselves 

 in its orbits (Plate IX. fig. 11), in the sockets of the in- 

 ternal antenna?, in the branchial chambers, and under the 

 tail (Plate IX. fig. 10) — in the former case often destroy- 

 ing both eyes. It feeds with avidity on the mussel in 

 its adult state ; so that here is an instance of a helpless 

 young form avenging the destruction of the mature. The 

 shore-crab, again, is devoured by many fishes : thus in the 

 stomach of a Cottus bubalis I have found five or six speci- 

 mens, two entire and upwards of 2 inches across the carapace. 

 The Cottus, however, unfortunately came in the way of a large 

 frogfish, which found a place for it in its capacious stomach, 

 though nine full-grown flounders were already present. In 

 many parts of Britain and the continent the shore-crab is used 

 as food by man (and this is a safe-enough practice so long as 

 it is well boiled, internal parasites being abundant) ; but at 

 St. Andrews it is only employed occasionally for bait. 



Myriads of the young of this species in the zoea-stage 

 occur at the surface of the bay in autumn, and may easily 

 be kept alive, so as to show the subsequent stages of develop- 

 ment. 



Besides those already mentioned, many of the other forms 

 are very common, such as Stenorkynchus rostratus, Inachus, 

 HyctSj Portumnus variegatus, the Portuni, PhinothereSjEba/ia, 

 and Nejjkrcps in deep water, Porcellana, the Paguri, Galathea, 

 and Crangon between tide-marks, and in both regions Hijypo- 

 lyte, Pandalus, and Palcemon. In deep water swarms of Hyats 

 coarctatus for the most part take the place of H. araneus. As 

 a littoral form Palcemon squilla is local, but, in company with 

 Pandalus annullcornis, it is abundant in deep water. The 

 common shrimp is seldom captured by man for food. Pm-tumnus 

 variegatus is often the only form visible on the West Sands, 

 and is very plentiful. The rarer forms are Eurynome, Piri- 



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