THE LOBSTER KIND. 



329 



open parts of the deep, and seeking some 

 retired situation among the rocks, or some 

 outlet where they may remain in safety from 

 the attacks of their various enemies. For 



engaged in delivering itself from its trammels, or that 

 the time is prolonged, as is the case with the cray-fish ; 

 circumstances which are easily accounted for by an ex- 

 amination of the crust ; and it is certain that when 

 delivered it possesses great activity in effecting its escape, 

 and that neither the prawn nor the lobster devour, as 

 has been supposed, any portion of the old shell. 



In the specimen referred to, the case of the antennae 

 and palpi was perfect to their minutest extremities ; the 

 stalk also, and transparent covering of the eyes, were 

 uninjured, but the former was attached on its inferior 

 portion only, the superior half hanging loose, so that it 

 would soon have fallen away in the agitation of the sea. 

 The segments and joints of the posterior portion of the 

 body, with the caudal plates, were all joined together, 

 but without any intervening membrane ; and the infer- 

 ior parts from beneath the snout, including the jaws and 

 footjaws, chelaedlegs, with the sternal plate, oesophagus 

 and internal coat of the stomach, formed one connected 

 portion, with no further separation than arises from the 

 absence of every portion . of membrane. The whole of 

 these inferior portions was drawn very considerably 

 within the carapace ; and it was the latter section of the 

 surface only that showed a mark of the manner in which 

 the animal had delivered itself from its case ; and this 

 it did in a way not to be mistaken. Through the middle 

 of this space, ran a line as straight as if it had been cut 

 with a knife, and evidently formed by a natural process 

 of separation : for it even proceeded through the centre 

 of the snout, to the terminal pointed process, at the root 

 of which it turned off' on the right side ; so that the 

 least effort of the animal was sufficient to aflbrd it a 

 passage. 



The observation here made on a very perfect specimen 

 that came into my possession by great accident, has been 

 further confirmed by a careful examination, both of the 

 living lobster, in which an obscure line is perceptible, 

 where the natural separation takes place : and also of a 

 specimen of small size, in which the sloughing or natural 

 process of division had only begun. In the latter case a deep 

 channel had been formed on the external part, nearly 

 half through the carapace ; while the internal portion 

 still remained firm; but I have little doubt that if the 

 creature had lived but a few days longer, the separation 

 would have been complete, and the animal would have 

 escaped from its prison. 



The growth of the young of the long-tailed Crusta- 

 ceans, is well known to be exceedingly rapid ; and there 

 seems reason to believe that the process of exuviation is 

 repeated at least two or three times in the course of the 

 first year of their age. In the course of a summer, 

 among many prawns one or two may always be found in 

 a state that indicates the having lately passed through 

 this process; but about October or November they all 

 seem to undergo it at once, the breeding season finishes, 

 and no further change in the shell takes place until the 

 approach of the spring. It is not improbable that the 

 general opinion is correct, which limits the exuviation 

 of the adult animals to once in the year; but from the 

 narks of old injuries, and the incrustation of parasitic 

 animals, I have come to the conclusion that in advanced 

 age the lobster does not throw off its case with any regu- 

 larity, and perhaps not at all. 



When about to throw off its exuviae the crab com- 

 monly retires to some secret place, in the near neigh- 

 bourhood of rocks that will afford it shelter when unable 

 to escape from danger, or defend itself from enemies. 

 Its craving appetite seems also at this time to be sus- 

 pended ; but the particular subject of my observation 



some days before their change, the animal 

 discontinues its usual voraciousness ; it is no 

 longer seen laboriously harrowing up the sand 

 at the bottom, or fighting with others of its. 



differed from others, in wandering into a crab-pot at this 

 period, in search of food; and being known by the 

 fishermen to be what is called peel, that is, about to 

 throw off its crust, it was transferred to the safe custody 

 of the store-pot, on Saturday, July 30th, where, on the 

 morning of August 1, it was found just then delivered- 

 from its covering. As quickly as possible, and without 

 injury, the living crab and its empty representative were 

 brought to me: and the following is a description of the 

 exuviae. 



The longest diameter of the carapace was 6$ inches ; 

 compass of the largest chela, and length of the flap or 

 tail, severally 3f inches: the individual a female, or 

 what is termed by fishermen a Bon Crab. The carapace 

 was sound, except on its under surface, where in its 

 ordinary state a curved line passes backward from the 

 jaws to the hinder part of the body. When caught on 

 the 30th this portion was observed by the fishermen to 

 be loosened ; and now the portion included between this 

 waved line and the sternal plate, was entirely separate 

 and fallen inward. The sheaths of the antennae and 

 palpi perfect ; one eye gone, the other remaining, with 

 the transparent covering perfect, the stalk loosely attached ; 

 the tail and all its appendages perfect ; the sternal plate 

 beginning to break across in the middle, leaving to each 

 portion a pair of legs on each side ; but this not being a 

 complete or natural separation, may have been produced 

 by the weight of the limbs alone, or the efforts of the 

 animal. The chelae and legs perfect in all their attach- 

 ments, the membranes unbroken ; and the flat bones 

 which occupy the middle of the muscles and serve them 

 for tendons or points of attachment for motion, were un- 

 injured and fastened to each joint, their distant extrem- 

 ities hanging loosely in the cavity of the case of the limb. 

 The coverings of the branchiae were perfect to their mi. 

 nutest extremities ; and besides the internal coat of the 

 stomach, the whole internal skeleton of the animal was 

 thrown off without fracture or displacement: including 

 the two motive bones or levers that pass through the mid. 

 die of the body from the jaws, to be attached to the in- 

 ternal dorsal aspect of the carapace: where formerly 

 attached, however, to the carapace they hung loose. The 

 curious bony articulations of the grinding apparatus of the 

 stomach, which renders the digestion of these Crusta- 

 ceans analogous to the rumination of quadrupeds, toge- 

 ther with the double crustaceous body (perhaps gland) at 

 the pyloric orifice, and the whole of the bony crusts or 

 chambers that receive the muscles which move the legs, 

 were disengaged with displacement. 



The Living representative of this wonderful skeleton 

 measured 7 inches in its longest diameter, the compass 

 of the largest chela, and length of the flap or tail, 4 

 inches; the weight 24J- ounces, being 5J ounces less 

 than an ordinary crab ef the same dimensions, weighed 

 with it for comparison. It was plump, having much 

 the appearance of a lump of dough enclosed in a mem- 

 brane ; and it was also equally soft, with scarcely more 

 power of motion : appearing sensitive only when pressed 

 on the under surface of the carapace. The colour above 

 was red, beneath a pale yellow, the flap purplish ; the 

 bristles on the legs fully formed, but soft, which is the 

 more worthy of notice, as I have seen the Procellana 

 platycheles, in which villosity forms a conspicuous 

 character, entirely naked when just escaped from the 

 crust. On cutting open the legs and chelce, the bonj 

 plates to which the muscles are attached, and which 

 serve for tendons, were found as soft as wet parchment, 

 and towards the extreme joints, could not be distinguished 

 with certainty. On breaking off the largest chela at the 

 2 i 



