174 Mr. A. H. HassalPs Catalogue of Irish Zoophytes. 



Grantia*. 



Grantia compressa ! G. foliacea of Montagu. 



Adhering to the under side of rocks above low- water mark ; Monks - 

 town. 



G. Coronata. — Monkstown : same as the preceding. 



MlLLEPORA. 



Millepora polymorpha, Linn. 



Millepora informis, Lamarck. — Dublin bay ; not common. 



Millepora lichenoides. " This Millepora has slender semicircular 

 plates which constantly grow horizontally." Lamouroux makes this 

 a Melobesia under the name Melobesia pustulosa. It ought, I think, 

 to be considered a Madrephyllia, under which head Dr. Johnston has 

 placed it. M. byssoides, Lamarck. 



CORALLINA. 



Corallina officinalis. There are several well-marked varieties of 

 this Corallina cylindrica. 



" Corallina rubens sive muscus marinus."— Park. 



" This coralline, when magnified, appears to grow in branches, al- 

 ways dividing into two parts, consisting of long cylindrical joints 

 connected by small tubuli." — Ellis. 



C. rubens, var. spenophecos. 



The above four corallines are found attached to rocks at Bray 

 Head, near Dublin. 



It is only by an extensive examination of catalogues similar 

 to the foregoing, that we shall be able to arrive at any certain 

 conclusions regarding the geographical distribution of zoo- 

 phytes, and the changes in the growth and habits occasioned 

 by the different localities in which they are met with. On 

 reference to the preceding list, it will appear that many spe- 

 cies common in the North of England and Scotland are either 

 not to be found at all on this coast, or are so sparingly ; and 

 on the other hand, many that are rare on the English coast are 

 abundant on the Irish. Thus, Thuiaria thuja, common in 

 the North of England, has never, I believe, been noticed on 

 any part of the coast of Ireland, and certainly not on that 

 embraced in the present catalogue. 



Again, I have never met with F. truncata and F. carbasea, 

 both very common on the coasts of Northumberland and Dur- 

 ham, and also occasionally found upon some parts of the Irish 

 coast. Many species of Plumularia, and two or three of Ser- 

 tularia, are wanting in these bays ; and the genus Eschara ap- 

 pears to be absent not only from this part but from the coast 

 of Ireland generally ; while Thoa Beanii, Discopora hispida, 



* See Grant iu 2nd vol. of Edin. New Phil. Journ. 



