Mollusca of St. Andrews. 349 



Lima Loscombuj G. B. Sowerby. Oj). cit. ii. p. 85, 

 V. pi. 25. f. 4. 



Single valves occasionally appear in the fishing-boats ; 

 perfect specimens are found in the stomach of the cod. 



Fam. 5. Mytilidae, Fleming. 



Genus 1. Mytilus, L. 



Mytilus edults, L. Op. cit. ii. p. 104, v. pi. 27. f. 1. 



Forming by their vast numbers a most important mussel- 

 bed at the estuary of the river Eden. Multitudes of the young 

 animals, besides, form a coating to the posts of the salmon- 

 nets, to rocks, stones, and tangle-roots in various places. 



Mytilus modiolus, L. 0/?. cit. ii. p. Ill, v. pi. 27. f. 2. 



Frequently thrown ashore after storms, and brought by the 

 fishermen from deep water. Monstrosities and varieties are 

 common ; and there is no shell so prolific in parasitic or com- 

 mensalistic growths ; pea-crabs and pearls are common in 

 their interior. Young forms (bearded) occur in chinks of 

 the rocks between tide-marks. 



Genus 2. Modiolaria, Beck. 

 Modiolaria marmorata, Forbes. Op. cit. ii. p. 1 22, v. pi. 28. f. 1 . 



Abundant in the tests of Ascidia sordida, and sometimes 

 found in a free condition on the West Sands after storms. 



Modiolaria discors, L. 0]p. cit. ii. p. 126, v. pi. 28. f. 3. 



Occasionally attached to the roots of Fuci near low water, 

 and to the top-shaped fronds of Jlimanthalia lorea. 



Modiolaria nigra. Gray. Op. cit. ii. p. 128, v. pi. 28. f. 4. 



Fine specimens occur in the deep water of the bay, and also 

 in the stomachs of cod. 



Genus 3. Crenella, Brown. 

 Crenella decussata, Montagu. Op. cit. ii. p. 133, v. pi. 28. f. 6. 



Not rare in the stomachs of cod and haddocks, though 

 perhaps swallowed in the first instance by other fishes. 

 Ann. (b May. N. Hist. Ser. 4. Vol. xiii. 25 



