MOLLUSCA. 
65 
Mytilus modiolus , L. Op. 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 
the interior. Young forms (bearded) occur in chinks of the 
rocks between tide-marks. 
Genus 2. Modiolaria, Beck. 
Modiolaria marmorata , Forbes. Op. cit. ii. p. 122, 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. Op. 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 Himanthalia 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. 
Fam. 6. Arcidae, Lowe. 
Genus 1. Nucula, Lamarck. 
Nucula nucleus , L. Op. cit. ii. p. 143, v. pi. 29. f. 2. 
Common in the bay; brought in by the fishing-boats, and 
frequent in the stomachs of cod and haddocks. 
Nucula nitida , G. B. Sowerby. Op. cit. ii. p. 149, v. pi. 29. 
f. 3 & 3 a. 
Not rare off the East Bocks in sandy gravel between the 
rocky ridges, and in the stomachs of haddocks and cod. 
K 
