57 



bands on the note I had from him in reference to the find. 

 It was also got by the late Edward Waller, off Yalentia, 

 Ireland, in dredgings taken in the late Dr. Jeffrey's yacht. 

 Waller did not live to publish the result of these gatherings, 

 although some three years were spent at the work. Three 

 plates were drawn by Wild, in one of tliese he figured three 

 forms of Crenata, each differing somewhat in shape, but all 

 referable to the one species." 



Your find, he says, off Dog's Bay, and mine off Dublin, 

 complete the list of British examples. 



The apparently world-wide distribution of this form of 

 Lagena, considered in conjunction with the fewness of the 

 specimens obtained from each known locality, is a singular 

 fact which must admit of some explanation, though what 

 that explanation may be, I am not sure that I can offer 

 even a probable conjecture. Some forms of Lagena, where 

 they are present at all, are to be found in abundance, such 

 as Lagena striata, costata and clavata. Others are less 

 common, but still are usually found in tolerable plenty; 

 while Lagena crenata is said to be everywhere scarce, 

 though its form is so remarkable that it could not be over- 

 looked by anyone searching a sample of marine deposit, and 

 therefore I conclude its variety must be admitted. 



Can it be supposed that the sarcode which forms a test of 

 this particular shape is distributed in only small quantity, 

 and yet so widely over the sea-bed ; or might it not seem 

 easier to believe that all the sarcode which assumes a flask- 

 shape, that is all the varieties of Lagena, may take the form 

 of any of the varieties and all of them in succession, thouo-h 

 some shapes are more frequently assumed than others ? 



According to this view the forms are interchangeable in 

 successive generations, the forms taken depending possibly 

 on varying external and internal conditions. 



