162 



LESLIE B. AREY AND W. J. CROZIER 



culatus. The predominating tint of the periostracum upon the 

 valves is green, but in the depressions between the ridges upon 

 both jugum and pleura a brown substance is evident. The 



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Fig. 1 Photograph of a Chiton tuberculatus L. on natural rock substratum, 

 from a moderately protected station, at low tide; about six years old, natural 

 size. Note epizoic barnacles (Tetraclita porosa Dar.), also, in the upper right 

 corner of the photograph, a cluster of Modiolus, and, on the posterior margin of 

 the girdle, two fecal masses. 



tubercles on the pleurae, in specimens less than 3 cm. long, are 

 tipped with blue. In very young chitons (less than 0.9 cm.) the 

 'scales' covering the girdle are colored opposite the anterior margin 



