Variati072s A7nong Scyphotnedusce. 



559 



the number of specimens tabulated was less than one-third of the 

 entire number in the preceding series. This is due in part to 

 the poorly differentiated stage of these organs in the early 

 ephyra, the gonads being entirely lacking, and the mouth-lobes 

 being often so contracted as to 

 render certain determination im- 

 possible. 



In Table II is shown the range 

 of variation so far as accurate 

 data are at command, including 

 as in Table I divergencies or 

 lack of correlation between the 

 two sets of organs. 



As will be noted, out of a 

 total of 486 specimens, only 12 

 or 2.68 per cent vary from the 

 normal. 



In several figures are shown 

 illustrationsof these aspects of our 

 subject. In Fig. 5 is shown a 

 sketch of one of these, in which 



there are but two oral divisions and two gastric pouches. One 

 might suppose the directly opposite relations of these organs as 

 figured to be unusual, but when compared with Figs. 6 and 7 it 

 will be seen to be quite in keeping with that found in almost every 

 case, that is, the angles of the mouth correspond with those of the 

 stomach so that the pouches of the latter of course occupy inter- 

 mediate positions. In other words, the angles of the mouth 

 occupy the perradii of the body while the gastric pouches or lobes 

 occupy the interradii. 



A comparison of figures will readily show the lack of correlation 

 of these organs with those of the marginal system, and at the same 

 time the close correlations between themselves, the latter being 

 likewise evident in the data of the table. 



Additional data of a similar sort will be presented in connection 

 with the second series, a comparison of which will still further 

 emphasize the small ratio of variation as compared with that 

 of the marginal organs. 



Fig. 8. Ephyra with seven gastric and oral 

 lobes, and ten marginal lobes. 



