E, IMPEKTAIIS. — YOTTNG SPECIMENS. 



81 



veiy young EupIecteUa tlie inmate is more often absent than 

 present. 



I may here add that the sieve-plate of young E. imperialis 

 is perhaps less frail and less liable to be lost than in E. marshalli 

 of a similarly small size ; for, I have found it preserved intact 

 in most cases of the former, while it was broken and lost in the 

 majority of the latter. Further I may record that whereas in 

 young E. imperialis the sieve-plate was always only flatly convex, 

 it was often, though )iot always, much more prominently so in 

 individuals of the other species in nearly the same stage of 

 growth. 



The approximate numbers of transverse and longitudinal 

 beams of the skeleton, as counted on four small specimens of 

 E. imjierialis, were as follows : 



A comparison with the numbers of corresponding beams in 

 fully adult specimens as given on p. 08, will at once show that 

 those of the longitudinal beams in the young (last row of the 

 above table) are, generally speaking, nearly equal to, or at any 

 rate not widely at variance with, the same as counted at the lower 

 end of mature specimens. This should mean that in the basal 

 region the longitudinal beams develop to their full or nearly 



