296 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



As a rule the degree of infection by Lymphocystis of 

 flounders from the Lune is slight. But occasionally a 

 specimen turns up in which the infection is very strong. 

 PI. VI. represents a fish which was forwarded to us a 

 week or two ago by Mr. John Wright. In this case a 

 large portion of the skin on both sides, but particularly 

 of the ocular side, is covered with single and multiple 

 Lymphocystis individuals. In this case emaciation of the 

 fish was very marked. 



Pearl-like Concretions in Fish Tissues. 

 In a gurnard (Trigla hirundo) dissected by Mr. 

 Chadwick, at the Port Erin Biological Station, there 

 occurred a number of small pearl-like bodies adhering to 

 the layer of peritoneum covering the intestine. The} r 

 were small, from 1 to 2 mm. in diameter, round or oval in 

 shape. Their colour is reddish brown towards the centre, 

 and light towards the margin, where the light is trans- 

 mitted through the substance of the concretion. They 

 were attached to the peritoneum by very delicate pedicles. 

 They cut easily, and in meridional sections through the 

 centre they present the general appearance of a decal- 

 cified pearl such as occurs in the mantle lobes of Mytihis. 

 In no case examined were there any distinct signs of a 

 nucleus possessing any obvious structure. The concre- 

 tion is made up of a great number of concentric lamellae, 

 which seem to consist of wavy bundles of connective tissue, 

 which stain a deep blue with Mann's methyl-blue 

 staining fluid, in the same manner as ordinary connective 

 tissues. Round this margin is a layer of different 

 material, which has a slightly different staining reaction, 

 and which seems to be continuous with the peritoneal 

 strand which forms the pediels. Round the margin in 

 this peripheral layer are small areas where there are small 

 collections of densely-staining granules. 



