Some Causes of the Disintegration of Shells. 14I 



constituent {Ostracoblabe). On removing one of these fruits 

 we see that the fungoidal filaments are really attached to it. 

 A young fruit in course of development shows this still more 

 clearly. The algal element of Vej^rucaria shows filaments 

 having a great resemblance to Hyella ccespitosa, though their 

 form is somewhat altered owing to its living in conjunction 

 with a fungus and not as an independent organism. 



The law of sympathetic selection of colour in nature is well 

 known. Animals, plants, and insects all display this quality 

 in a marked degree. Molluscs are apparently not devoid of 

 this power of selection. 



Batters has noticed this fact with regard to the yellow 

 periwinkle, which lives among Fuci. We may expect shortly 

 an interesting paper showing the protective colouring adopted 

 by these molluscs. 



I conclude my remarks on the perforating seaweeds with a 



list of the Irish species. This is the first time a complete list 



of the Irish species has been published. For it and for help 



and every facility for examination of the group, I am indebted 



to Professor Johnson. 



Hyella caespitosa, Boriiet et Flahault— Cloutarf, 1S92, Prof. John- 

 son, B. and W. coasts of Ireland. 



PIcctoneiYia terebrans, Thuret — Clontarf, 1892, Prof. Johnson 

 and R. Hensman. E. and W. coasts of Ireland 



MastliTOCoIeus testarum, Lagerlieim — Roundstone, 1S93, Prof. 

 Johnson and R. Hensman. E. and W. coasts of Ireland. 



Comontla polyrhiza, Bornet et Flahault— Shores of Galway Bay, 

 1891, Prof. Johnson. E. and W. coasts of Ireland. 



Conchocelis rosea, Batters— Clontarf, 1893., Prof. Johnson and R. 

 Hensman. 



Verrucaria consequens, Nyl. — Bundoran, 1894, Prof. Johnson 

 and R. Hensman. It has since been found on the east coast. 



It is probable that all the species mentioned, except C. 



rosea, are generally distributed round the coast of Ireland. 



