122 Unircrsifij of California Publications in Zoology [Vol. li 



3. The number of anterior and posterior teeth and seizing 

 jaws increases as the animal grows larger, the rate of increase 

 being greatest in posterior teeth and smallest in seizing jaws. 

 Therefore, the specitie value in number of these structures 

 depends not only on the extremes of variation but, quite as 

 definitely, on the amount of variation in the rates of increase. 



4. The maximum number of animals whose lengths vary 

 within 1mm. from 13, 15, 17, 19, 21. 23 and 25 mm. have the 

 characteristics summed up in table 11. 



5. The average proportions of the various regions of the body 

 relative to animals varying between 12 and 14, 14 and 16, 16 

 and 18, 18 and 20, 20 and 22, 22 and 24, and 24 and 26 mm., are 

 summed up in table 12. 



It is needless to say that, in tables 11 and 12. the figures are 

 not very reliable in the case of animals under 18 mm. in length 

 because of the small niimber considered. For the others, how- 

 ever, the figures ought to hold good within a small range of 

 variation if determined on the basis of a moderately large number 

 of specimens. Furthermore, if S. calif ornica should be discovered 

 elsewhere than in California waters, these tables will furnish 

 means for ascertaining the direction and degree of variation due 

 to differences in locality. 



DISTRIBUTION 



Altogether 236 specimens were obtained, of which one was 

 taken in a Nansen closing net haul (no. 2858) made from 150 

 to 100 fathoms, two in a similar haul (no. 2840) made from 10 

 to 5 fathoms, and the remainder from the surface. None were 

 obtained prior to October 24, 1911, nor, so far as the hauls have 

 Deen examined, since October 28, 1911. Furthermore, of the 

 twenty-one surface hauls made, all hut two obtained the species. 

 Now the same localities from which this species was obtained 

 were thoroughly investigated between the surface and 75 fathoms 

 during every month of 1911, except September, and it seems 

 probable that <S. calif ornica was not present prior to August 11th 

 nor after November 27th, the former being the last date ot 

 hauling previous to October 24th, and the latter being the first 



