way to be recommended. Not only does it often lend an unnatural waxy 

 appearance, but specimens so treated are prone to become increasingly 

 unkempt and frowsy with adhering dust. Mounting likewise is inadvisable 

 if it entails solid fixation to a card or tablet, as the interior of the shell in 

 chitons is often hardly inferior in interest and beauty to the dorsal surface, 

 and it is better to keep one's specimens in such a manner that they may 

 readily be subjected to examination from all aspects. My own practice is 

 to use shell-vials for the smaller shells, cardboard trays for the larger, and 

 to resort to the more expensive glass-topped boxes only for certain special 

 subjects. Certain quite crucial classificatory features of chitons are found 

 in those marginal structures whereby the valves interlock with the girdle 

 and with one another, and are well seen only if the valves are entirely 

 disarticulated. It is therefore wise to prepare such disarticulated series for 

 as many species as one's material permits, marking those valves, the 

 identity of which is not easily apparent from their form, with small Roman 

 numerals in India ink according to their position. III, IV, V, or VI. In 

 disarticulation it is necessary to be extremely careful not to break either the 

 insertion teeth or the sutural laminae, and it therefore becomes the part of 

 wisdom to take the precaution of first soaking up such specimens in warm 

 fresh water in order to reduce the extremely tough resilience often pos- 

 sessed by the girdle to something resembling flaccidity. The freed girdle 

 may in its turn be used either in the preparation of whole mounts in balsam 

 or mounts of the loose scales. I usually like to prepare slides of both 

 categories as well as of the radula, not failing to record the exact animal 

 or shelly parts from which they were taken. I also occasionally make clear 

 mounts in balsam of the entire animal, shell and all, where the animal is 

 small enough to clean and mount well. One learns much from these. 



The principal enemies of a collection of chitons kept in the dry state 

 are dirt and the common museum beetle. Both hazards can be reduced to 

 a minimum by keeping the collection in a cabinet with tight drawers, with 

 a generous and frequently replenished scattering of naphthalene flakes or 

 moth-balls in each drawer. It goes without saying that the more careful 

 and thorough the initial preparation and cleaning the less subsequent 

 trouble there will be. 



However this may be, the desirability of preserving a fair proportion, 

 if not the whole, of any given catch in alcohol, wherever scientific studies 

 are subsequently to be carried out, can not be too strongly emphasized. 

 By so doing a collector will certainly find his efTorts to count far more in a 

 lasting way. Many important characters of chitons are greatly obscured 

 and sometimes lost entirely through subjection to the process of drying. 

 This in some cases involves even such fundamental matters as family char- 

 acters, and many a scientifically priceless specimen has lo3t a large part 

 of its value because of the collector's neglect or ignorance of this truth. 

 In consequence, there is no doubt that the lack of material suitably pre- 

 served in alcohol has, more than any other single circumstance, delayed 

 our understanding of this extraordinary group of creatures and has involved 

 their study with much needless uncertainty and confusion in the literature. 



(41) 



