36 



no doubt being that such a long time bad elapsed since 

 the animal's last opportunity of feeding that the contents 

 of the stomach had been digested and had passed on. 

 Consequently we found it important, in enquiries into 

 the food, to state that, if the specimens cannot be exam- 

 ined as soon as collected, they should be killed at once so 

 as to stop digestion. 



The food of the Cockles examined in the laboratory 

 consisted of spores and other young stages of lower 

 Algse. filamentous Algas, fragments, and other vegetable 

 debris, Diatoms, Foraminifera, Sponge spicules, fragments 

 of minute Crustacean appendages, such as Copepoda, and 

 of the larval stages of higher Crustacea, all mixed with 

 sand grains. 



We have found that most cockles sent to the laboratory 

 are infested by the minute Copepod, Lichomolgus agilis, 

 recently described by Mr. Scott, but there is no reason to 

 think that this commensal is in any way injurious to 

 the cockle. There is also a similar Copepod in the 

 mussel. Although there are five species* of cockle (the 

 genus Gardium) which are found in this neighbourhood, 

 still all the cockles sent to market belong to the one 

 common species C. edule. Some of the men speak ot 

 more than one kind, and of a smaller species, but although 

 specimens from different beds may vary a little, in size, 

 and colour, and thickness of shell, all that have been sent 

 to the laboratory for examination, both large and small, 

 are C. edule. Some specimens which were sent by Mr. 

 Dawson on April 8th from one of the Morecambe Bay 

 beds are very brown on the outsides of the shell and even 

 along the inner edge of the valves and over part of the 

 mantle lobes and siphons. We found that this staining is 

 due to a deposit of amorphous oxide of iron, caused 

 * See Fauna of Liverpool Bay, vols. I. and III. 



