OF NORTHUMBERLAND AND DURHAM. 2G9 



diminish the aj^parent disproportion between the two coun- 

 ties. 



The number of Chlorosperms native to our coast seems rela- 

 tively very small ; but this is probably more in appearance than 

 in reality. A large proportion of that class are very minute or 

 even microscopic plants, which may well escape detection on the 

 sea-shore. I have myself found, in a small aquarium, two unre- 

 corded species, the germs of which must have been brought from 

 the coast near Sunderland. These are included in the catalogue. 



The nomenclature and arrangement which I have adopted are 

 those of Dr. Harvey, except in the class Rhodospermeae, where 

 I have followed the more recent classification of Professor 

 Agardh — an arrangement " based upon a more accurate examina- 

 tion of the conceptacular fruit or ' sporiferous nucleus.' " 



At the end of the catalogue will be found a table indicating 

 the changes of name which have been thus introduced. 



I am indebted to many of my friends for valuable assistance 

 in the preparation of this catalogue by the loan of books and 

 specimens, and in many other ways. To all such I would, in 

 conclusion, offer my sincere thanks. It is only by the com- 

 bination of the labours of many, even in the pursuit of so 

 limited and compact a subject as the present, that tolerable 

 completeness is to be attained; and there is yet ample scope on 

 our coast for the exploration of the enthusiastic phycologist. 



SUNDERLAM>, Sept, 17, 1860, 



VOL. IV., PT. IV. 2 K 



