212 Papers from the Department of Marine Biology. 



maximum in the fourth and eighth specimens of the bottom line of 

 figures, plate 2. Associated with this is the producing, attenuating, 

 and rounding of the base, best shown in the two figures alluded to above. 

 The sculpture in most instances follows the parent type, but in some it 

 is decidedly different, and the variation does not follow a uniform 

 direction. 



One type of variation is shown by figure 4 of the bottom line, plate 2, 

 in which the ribs are almost obsolete and very widely spaced. Another 

 is represented by specimens 14, 15, and 16 of the top line, which are 

 much darker, much narrower, and have the ribs much more crowded 

 than the members of the check series. These two departures are so 

 pronounced that they would probably have been considered distinct 

 species and deemed not very closely related to the parent stock by 

 past workers in this group unfamiliar with the history of the specimens. 



THE "KING'S ROAD TYPE" OF CERIONS. 



The 8 specimens figured on plate 3 were taken at random in the same 

 way that those of the "White House Type" were selected, from a large 

 series collected in the Bahamas. They may therefore be taken as fairly 

 typical representations of that type. Most of the first generation pro- 

 duced by the colonies of this type have not yet attained the adult stage. 

 The material at hand enables us to say that the offspring of this group 

 show changes from the parent stock as great, if not greater, than those 

 observed in the first generation of the "White House Type." 



The three specimens from the second Ragged Key north of Sands 

 Key (plate 3, figs. 1-3, bottom line) are uniformly larger, darker, and 

 with more attenuated base than the check series. 



The Boca Grande Key specimens (plate 3, figs. 4-7, bottom line) 

 show great variation in size and also in coloration, but there is as yet 

 not enough material to make comparisons. 



The greatest variation is shown by the first generation from the 

 south colony on Loggerhead Key (plate 3, top row). Although only 

 3 specimens were found that had attained full growth, most of the others 

 figured have attained a stage so near maturity that we can readily see 

 that they are much larger, decidedly more attenuated, and usually 

 darker than the check series. 



It is to be hoped that next year will yield a larger series of the first 

 generation of this type. The second generation is also looked forward 

 to with considerable interest, since in it the germ-plasm will have been 

 subjected to the new environment, and this may entail still greater 

 changes than have yet been observed, i. e., the effect of the new con- 

 ditions upon the germ-plasm. 



In the following plates all figures are natural size excepting plate 6, 

 which is reduced about one-seventh. 



