No. 5.] VARIATION AMOXC, 11 \ Y'A'( >M EDUSA /:'. 



229 



I-'u,. 2. 



the 



thick, velum not specially prominent. Manubrium subconical, 

 bearing four oral tentacles which divide dichotomously into 



small clusters of tentacles. Figs. 

 2-4 give good general impressions 

 of the animal. The very minute 

 size made necessary the constant 

 use of the compound microscope 

 in all the examinations. 



In general this medusa seems 

 to be fairly constant in form, 

 color, and organic symmetry. 

 Only the radial canals, and tenta- 

 cles - - marginal and oral - - were 

 noted, no gonads being present as 

 yet. Of the tentacles note was 

 taken of the number of groups, 

 number of individual tenta- 

 cles increasing in these with 

 age. The total of all sorts 

 of variations noted hardly 



\exceecled two per cent. 



KK;. 3. 



The variation in radial 

 canals was usually corre- 

 lated with that of the ten- 

 tacles. In Fig. 2 is shown 

 a trimerous specimen, in 

 which there was a perfect 

 correlation of all the or- 

 gans, including oral tenta- 

 cles (several specimens 

 noted). In Figs. 3 and 4 

 is shown a pentamerous 

 form, in which there ap- 

 peared little meristic cor- 

 relation. For example, it will be seen that while five sets of 

 tentacles correspond with the five radial canals, two had but a 



FIG. 



