288 Pi*ofessor Owen on Collecting 



middle-sized specimens should be kept by themselves, or sewed up in 

 a bag, if placed with others in the same jar or bottle. Rare and 

 beautiful kinds, with transparent glass-like shells, may be captured 

 by the towing-net in tropical seas. The minuter kinds have been 

 commonly neglected, especially those of fresh water ; any such 

 species observed darting about in the fresh water of foreign countries 

 should be preserved in tubes, in spirit or solution No. I. The 

 larger kind^ of marine Crustacea should be suffered to die in fresh 

 water before immersion in the preserving liquor. The different 

 kinds of King-crab {Lhnulus), usually found on sandy or muddy 

 coasts, are particularly worthy of preservation in spirits or solution, 

 with the ova or young. 



In preparing Crustacea for drying, care is to be taken to preserve 

 all their external parts as perfect, and as expressive of the natural 

 progressive action, as possible. Crabs and lobsters should be cleaned 

 out as soon as practicable, i. e., the soft internal parts and the flesh 

 should be removed, and they should be soaked in fresh water pre- 

 vious to drying. The claws when large require to be separated at 

 each joint for the purpose, and then refixed, or a small piece may be 

 neatly removed and afterwards replaced. When dried, the specimens 

 should be wrapped in very soft paper, and then packed in cotton, so 

 as not to allow of their being displaced in the case, nor to touch one 

 another. It is desirable, with regard to brilliantly-coloured crabs, 

 to wash them over, after they are dried, with a thin coat of the fol- 

 lowing varnish ; — 



Varnish for Crabs, Eggs, &c.. No. I. 



Common gum, . . . . 4 oz. 



Gum tragacanth, . . . . J oz. 



Dissolve these in three pints of water, add to the solution 20 grains 

 of corrosive sublimate, and 20 drops of oil of thyme, dissolved in four 

 oz. of spirit of wine ; mix it well, and let it stand for a few days to 

 separate ; the clearer part is to be used as varnish ; the thicker part 

 forms an excellent cement. 



A very important subject of investigation is the development of 

 the Crustacea, from the earliest period at which they can be observed, 

 to the assumption of the mature or parent form. The eggs, usually 

 of some bright colour, attached beneath the tail of the female crab, 

 lobster, or shrimp, should be examined for this purpose ; the embryo, 

 if in course of development, may be readily seen by opening the egg 

 under a moderately magnifying power (see the note on microscopes). 

 Drawings of the different forms or shapes of the embryo should be 

 made, if possible, and the eggs and embryos preserved in spirits or 

 solution in small glass tubes. 



