No. 2.] MORPHOLOGY OF THE MYXINOIDEI. 



219 



In 62 individuals with 12 gills the following dental formulae 



occurred • 1 a 1 10 1 9 i 8. 8 ^ I J-^- 1-9-1 i-O- 



4 li). I i_o ft 



^ 101 '9~' " 



1 U|i#. 10 



_9_ 

 10 



10. 2 1 



10' ^ "9" 



10. 

 10 



10 

 10 



11 



10 



12 

 10' 



1 ^^ 

 -^10 



1 1^ 

 -^11 



_9_ 

 10' 



ii 

 10' 



12 

 11- 



10 



1 



i_o 

 "9 



i_i 



'9~ 



1 1-0 

 1 9"' 



1_0 

 '9'' 



1 

 10 



11 

 10 



10 

 10' 



10 

 10' 



1_0 

 "9' 



11 



10 



1 

 I 9' 



10 

 10' 



11 



1 0' 



On combining the dental formulae of the ii-gilled and 12- 

 gilled variations, the following numbers were found to obtain 

 in the Z6 individuals whose dental formula was carefully 

 examined on both sides of the dental plate. 



Total number 



86 



In the series of 162 specimens from Monterey Bay examined 



by Mr. Jackson, the following dental formulae were observed : 



Branchial formula, 10-10 : — 1 %\%. 



Branchial formula, i i-i i : — 1 



1 U. I H 8 11 I 1 410111 9 

 -L Q I 9 > ^ lo" I -9-, ■* 10 I To"' ^ 



10 3 11110 7 11 I 11 1 

 io» " 10 I 10' ' 10 I 10' -•• 



IJL 

 '8 ' 



11 1 



1 



11 



10 I 1_0 1 IJ) 

 10 I "9"' ^ ~<d 



11 

 10 



U 

 9"' 



11 



To 



11 

 10' 



12 

 10' 



10. 

 10 



U 

 "9" 



11 

 11 



Total, 50. 



10 



10' 



i_i 



8'' 



12 

 10- 



