Mollusca of St. Andrews. 



347 



PMline angulata and P. iiitida^ Rossia papilUfera, the Clios, 

 and the half hundred new British forms discovered bj Mr. 

 Gwyn Jeifreys in his frequent cruises in the surrounding 

 waters. The great beds, also, of Mytilus modiolus (called 

 "yoags "), which occur in from 3 to 15 fathoms near the shore 

 in many parts of the Zetlandic seas, present an interesting 

 contrast. It is this mussel (esteemed but a coarse bait at St. 

 Andrews) which is extensively employed by the Shetlanders ; 

 and in its collection many rare invertebrates are found amongst 

 the roots of the tangles and stones, which with the mussels 

 form huge muddy masses. The old ten-toothed " dreg " 

 noticed by the accomplished Prof. Edward Forbes is still the 

 chief instrument in procuring the 

 shell-fish, and is much more service- 

 able to the zoologist on such ground 

 than the dredge. In the fis-ure fjiven 

 by the facile pencil of the great 

 naturalist the rope is attached to 

 the eye of the dreg ; but in modern 

 times the fishermen more correctly 

 attach it to the head of the instru- 

 ment (after the manner of the ordinary 

 dredge), and fix the rope at the eye 

 of the dreg by a piece of spun yam ; 

 so that if the dreg gets entangled 

 the spun yarn gives way, and the 

 rope pulls the head of the dreg back- 

 wards, and disengages the teeth from 

 the tangles and stones. In trans- 

 verse section the teeth form a trun- 

 cated ellipse round the central iron rod. 



The nomenclature adopted is that of Mr. Gwj^n JeflEreys in 

 his valuable work on the British Mollusca ; and I am specially 

 indebted to him for his great courtesy in frequently aiding me 

 in doubtful cases, and also carefully investigating shell-ddbris 

 containing minute species, which otherwise miglit have been 

 overlooked. 



Class CONCHIFERA. 



Order Lamellibranchiata. 



Fam. 1. AnomiidaB, Gray. 



Genus AxoMiA, L. 



Anomia epkippium, L. Jeffreys, Brit. Moll. ii. p. 31, 

 v. pi. 20. f. l,la-le. 

 Not uncommon in the debris of the fishing-boats. 



