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W. J. CROZIER 



TABLE 1 

 Estimates of the quantities of bottom material sivallowed by Stichopus moebii at 

 certain localities in Bermuda. The calculations based on the number of Stichopus 

 present in the areas measured, their average size, and the assumption that they eat 

 twice each day 



* The number seems fairly constant in any one locality; for example, in the 

 small area studied on the south side of Marshall Island, between 600 and 700 

 young Stichopus (between 10 and 18 cms. length) were constantly present from 

 August to November. There is a very decided tendency for all those in one local- 

 ity to be of about the same general size. 



III. Employing the reasonable, and I believe exceedingly 

 moderate, assumption that, on the average, Stichopus fills the in- 

 testine two times each day throughout the year, and taking into 

 account the average size of the individuals locally concerned 

 (with the aid of fig. 1, A), the calculations exhibited in table 1 

 were made in order to obtain some idea of the magnitude of the 

 effects which may properly be ascribed to the feeding activities 

 of Stichopus. It is further assumed that the specific weight of the 

 bottom-material is the same in the different localities mentioned, 

 an assumption which is well within the limit of error of other 

 parts of the calculation. I have no desire to convey the im- 

 pression that these figures (table 1) possess any notable precision, 

 but I am unable to see that they could be made more exact with- 

 out the expenditure of an unprofitable amount of energy. 



It will be noted that any inadequacy attaching to these esti- 

 mates is in all probability such as to make the results too small 

 rather than too large. Yet the average figures appear to be of 

 considerable magnitude. It seems that for each square meter of 

 bottom, in the localities studied, between 2.7 and 29 gms. of cal- 

 careous deposits are passed through the gut of Stichopus each 

 day. This leads to the conclusion that on the average, in these 



