

of the missing valve. The absence of a valve produces no striking 

 change in the general appearance of the animal, and it would be 

 easy to pass one by among a quantity. These considerations incline 

 me to think that abnormalities in the valves may be less rare than 

 opposed. 



Injuries to the girdle often produce more or less irregular growth. 



-pecies having large girdle-scales, such as Chiton s. dr., or the 



large-scaled Ischnochitons, the loss of scales is repaired by the 



DJured area of scales much smaller in size, giving 



it a singular! \ ! appearance. 



Co i \ A ITON OF CHITONS. 



Chitons may be looked for on all but sandy coasts ; on these they 



are very rare. Some species, like Nutiallina, Enoplochiton* Acantho- 



' tc., are found upon the exposed rocks at or near high tide ; 



others like most 7 ton*, live under stones between tides or at 



lowest water; Km it is only by the use of the dredge that any 



roach to a full representation of the Chiton fauna of any locality 



can be obtained. e dredging outfit is required, how- 



ver nine-tenths of the species being vegetable eaters, live 

 in the littoral (including the laminarian and coralline) zone, and 



generally be taken in 25 fms. or less depth ; although num- 

 bers of species extend their rani:e to or beyond the 100 fm. line, and 

 a few (the genera Lepidoplewrut and Hanleya only) live in the cold 

 and dark abyssal region. 



hint knife is useful to the collector in detaching Chitons from 



rocks etc. ; and the specimens before they have time to curl 



nelves up, should be placed flat on a narrow strip of smooth 



wood like a ruler or lath well wetted with salt water, and bound 



down l.y windin- with s..ft twine or randle-wicking. This will keep 



them in a natural position until the tissues are relaxed, when they 



may be placed in alcohol, or cleaned by cutting away the foot and 



viscera. If this precaution is not taken they are apt to curl up in a 



shape which renders them alm^t useless for dissection or for cab- 



-pecimens, for they will break rather than flatten out. A large 



ler maybe thus set on a single stick. If th.-y curl up before 



- t. it is best to put them in a pan of salt water, where 

 will eventually straighten out, if al 



HIM. .iii. AI. NOTES ON i in I.ii i HATURE OF CHITONS. 



w species of Chitons were known to writer.-, upon shells 



