46 
with gentian violet and orange G, the nuclei and the cyst staining 
deeply with gentian violet). It is interesting to compare this 
with the cysts of epithelium surrounding the “ Pearl Trematode ” 
described by Dr. Jameson,* showing how very differently the 
presence of Trematodes affects different tissues. 
The encysted worm from the liver of the mussel was briefly 
described by me last year,! but very little structure was made out 
beyond two suckers and a conspicuous glandular excretory system. 
It is common at Budle and Holy Island, and was found sparingly 
at Amble. 
Besides the Trematodes from the mussel, many more were found 
in the other Mollusca associated with them in the beds, and these I 
examined whilst searching for the early stages in the life-histories 
of the above-mentioned forms. The results of these investigations 
have nearly all been already published.]; 
Many encysted forms were found in the Crustacea near the beds 
which I hope to investigate more closely hereafter. 
EXPLANATION OF FIGURES. 
Fig. I. — Part of Budle Bay at low water. 
Fig. II.— Mussels being put through screen, Budle. 
Fig. III.- — Mussel shell from Budle showing pearly excrescences due to Fohjdora 
ciliata. 
Fig. IV. - Section of Mantle of Mussel showing effect of Pohjdora ciliata. 
Fig. V. — Mussel with ridge of pearls— gills (a) : foot and left mantle cut away. 
Fig. VI. — Section of Foot of Mussel showing cyst of Echinoslomum secundum. 
Maps. — These are all on a scale of H in. = 1 mile. 
The areas occupied by Mussels are indicated by diagonal shading. 
Uniform shading denotes land, and sandy areas are shown by means 
of dots. 
* Op. cit. 
+ Northumberland Fisheries Report for 1905, p. 102. 
X Northumberland Fisheries Report for 1905, p. 100. Ann. and Mag. Nat. Ilist., Jan., 
1907, p. 102. Trans. Univ. of Durham Phil. Soc., 1906, p. 231. Trans. Nat. Hist. Soe., 
Northumberland and Durham, Vol. I., N.S., Part HI., 1907, p. 437. 
