74 Instructio)is in Zoolo(/i/ and Animal Physiology, 



A sketch or drawing of molluscous and radiate animals, of 

 which the form and colour are liable to be materiallj' altered 

 by death, or when put in spirit, will aid materially in render- 

 ing the description of the species useful and intelligible. The 

 Echinodermata should be soaked in fresh water previously to 

 their being put into spirit. Care must be taken not to crowd 

 too many soft-bodied invertebrata in the same bottle, and to 

 change the spirit or preserving liquor at least once, if not 

 often er. 



2. Fishes, — The mode and speed of swimming, living colour, 

 temperature, and any other peculiarity, should be noticed be- 

 fore placing the specimen in spirit. 



In very large specimens of the Shark or Ray kind, a section 

 of the jaws, with a part of the vertebral column, should al- 

 ways be preserved as wet preparations, and the remainder of 

 the jaws and vertebral column in a dry state. The eyes, eye- 

 lids, and part of the surrounding skin, should be preserved in 

 the saline solution. In less bidky specimens, the entire head 

 should be taken off by dividing the fish below the heart across 

 the upper part of the livei", by which means the mouths of the 

 oviducts, if it be a female, the heart, gills, and head are all 

 preserved together. 



The tail of a shark may be taken off a little below the anus, 

 and the trunk alone preserved for examination. If the trunk 

 be too large, it should be cut through above the pelvis, and 

 the parts contained in the hinder portion, as the claspers of 

 the male, should be preserved in spirit. If the specimen be 

 a female, separate the two oviducts through their Avhole length, 

 where they nm along the abdomen, on each side of the spine, 

 but keep them attached to the cloaca and its surrounding- 

 parts. 



If with young or eggs, take the whole out in the same Avay 

 without opening the oviducts. 



The heads of all fishes should be preserved, when specimens 

 are too large to be preserved entire. 



All external parasites, and those which infest the gills of 

 fishes, should be preserved. The alimentary canal should, in 

 all cases, be examined for the presence of entozoa, which, if 



