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Bashford Dean Memorial Volume 



in dorsal, lateral and ventral aspects; and our Figure 15, plate V, in which the teeth are 

 by photography enlarged to about 13 mm., i.e., about three times natural sizie. 



As will be seen in our table No. VIII, different authors have given different counts of 

 the rows of teeth in the jaws of their specimens. Mertens (1921), who is not included in 

 the table, gave 16 rows only for each jaw, upper and lower, of his fish. This is mani' 

 festly an error, due apparently to his failure to count the rows in the corners of the mouth, 

 where the teeth grade into shagreen. Garman (1884.1) counted 28 rows above and 27 

 below, but later (1885.1) corrected this to 26 and 25 respectively. From our illustrations 

 showing mouth and teeth (Plate III, figures 9 and 10), it is understandable why there is an 

 odd number of rows below, due to the median row at the symphysis of the lower jaw. 



Text-figure 10 

 An individual tooth of Chlamydoselachus X 6: A, upper front view; B, lateral 



view; C, ventral view. 

 After Garman, 1SS5.2. 



The figures also make it clear that toward the angle of the jaw the teeth become 

 smaller, the arrangement in rows more obscure, until finally it is only with great difficulty 

 that one can distinguish the rows and differentiate the teeth. We have found this true in 

 trying to count the rows of teeth in the jaws of our specimens, and only after days of work 

 did we succeed in developing a technique that enabled us to produce counts which, when 

 checked, gave the same numbers time after time for the same specimen. 



TABLE VIII 

 NUMBER OF ROWS OF TEETH IN JAWS OF VARIOUS SPECIMENS OF CHLAMTDOSELACHUS 



