HA RDWI CKE ' S S CIE NCE -GOS SIP. 



Si 



sembling an aurora borealis (see fig. 53) precisely the 

 same as from the corners of the more perfectly de- 

 veloped form, and I presume it is from this rudimentary 

 condition that all these perfect individuals I have now 

 discovered have developed, as I turned the Alga into 

 my tank after examining it, where it has remained 

 undisturbed to the present time. These Acineta 

 very much resemble the Floscula, but there is hardly 



particles. With small specimens enough has now 

 been done as regards removing the soft parts, but 

 where the forceps or pincers are at all large, they too 

 must be freed from their internal matter, and this can 

 be done by either removing them altogether and 

 withdrawing the contents by means of a flattened iron 

 hook, or by making a hole on the under side of the 

 limb and inserting the hook through that. When all 



Fig' 53. — Probable rudimentary condition of Acineta. 



any perceptible movement in them, and there is no 

 visible opening or mouth into the interior ; they are 

 also destitute of any gelatinous case or envelope. 



W. G. Cocks. 



ON THE PRESERVATION OF CRUSTACEA 

 FOR THE CABINET. 



THERE are few objects so interesting and yet so 

 comparatively scarce as a good collection of 

 ■Crustacea. No doubt the scarcity of such collections 

 is partly owing to the comparative difficulty attending 

 the drying and preservation of these animals, and with 

 this idea I wish to explain in a few words a method 

 which, although capable of improvement, is one that 

 I have found to answer the purpose fairly well. In 

 the first place, it is necessary that the specimen 

 should be operated upon as soon as possible after 

 death ; but where this is almost impossible, much of 

 the setting up can be attended to afterwards, so long 

 as the internal structure is taken out and the specimen 

 packed away in a dry place under the conditions 

 which I will now attempt to describe. Let us take 

 for example a specimen of the Norwegian lobster 

 {Nephrops Norwegicus) ; lay the specimen on a board 

 in its natural extended position, and with a sharp 

 knife sever the abdominal segments from the carapace. 

 When this is done the internal structure can be entirely 

 removed, and great care should be taken to do this as 

 thoroughly as possible, without injuring the external 

 skeleton. The carapace should also be removed, in 

 order to cut away the gills from between it and the 

 inner calcareous wall. After this has been carefully 

 done sprinkle the damp parts with fine powdered 

 alum, which will assist in drying the remaining 



the parts are'thus skeletonized, they should be set up 

 separately on a piece of soft pine board and the legs 

 and antennre held in suitable positions by means of 

 long pins, and it is very necessary to keep the several 

 parts of each specimen together, in order to avoid the 

 ludicrous mistake of fixing the abdomen of one to the 

 carapace of another which may be of different size or 

 sex. The dissected parts must now be slowly dried ; 

 and now is the period when a great risk is run of 

 entirely spoiling the specimens, for if they be exposed 

 to the glare of a hot sun or to too fierce a heat from a 

 fire, they will either bleach, or, in most cases, turn a 

 brilliant red ; but if care is bestowed on this part of 

 the preparation they will be ready after a few days' 

 exposure to what is best of all, a drying draught of 

 air, provided the weather is favourable, to set up for 

 the cabinet. As regards the setting up, the best 

 lesson in this is to be learnt by going and looking at a 

 live crustacean and following as nearly as it is possible 

 to do the attitude of the animal when standing 

 motionless, and by a few judicious placings of the 

 antennae, legs and forceps a specimen can be made to 

 look far more life-like than any specimen of lepi- 

 doptera or coleoptera in a cabinet. For readjusting 

 the dissected portions gum tragacanth is perhaps the 

 best, as of course it is desirable that no adhesive 

 matter should be visible after the creature is set up. 

 If the specimen has a sufficiently transparent carapace 

 it will be found advantageous to insert cotton wool 

 coloured in such a way as to bring the appearance of 

 the external skeleton as nearly as possible to that of 

 its living comrade ; for instance, black wool in the 

 carapace of an Astacus fluviatilis will often 

 render its outward appearance much more natural 

 than if it remained empty. For the treatment of 

 crabs the carapace should be carefully removed and 



