166 Sir F. A. Mackenzie on the Breeding 



9. Trichotropis acuminatus. Jeffreys in ' Malacological and Concho- 



logical Magazine,' No. II. p. 36. In Lerwick Sound : not un- 

 common. I found one specimen of the Chiton albus which was 

 half an inch long. 

 Pecten obsoletus, var. omnino alba. In Lerwick Sound ; only one 

 specimen. 



10. Crenella elliptica, Brown [Mytilus decussatus, Montagu] . In 

 Lerwick Sound : not uncommon. 



11. Area fusca^ In Lerwick Sound : a single valve. 



12. Montacuta substriata, Turton. Lerwick, attached to the ventral 



spines of the Spatangus purpureus, its usual habitat. 



13. ■ ferruginosa, Turton. Scalloway; a single valve. 



14. Lucina lactea. At Scalloway : rare. 



15. spinifera [Venus spinifera, Montagu]. In Lerwick Sound : 



rare. 



16. Cyprina minima, Turton. In Lerwick Sound: not uncommon. 



17. Astarte} triangularis [Mactra triangularis, Montagu]. In Ler- 



wick Sound ; one specimen only. 



18. Venus Virginea and var. Sarniensis, Turton. Lerwick: not un- 

 common. 



19. Anatina prcetenuis . Lerwick and Scalloway : rare. 



20. — — intermedia. Jeffreys in ' Malacological and Conchological 



Magazine,' No. II. p. 45. In Lerwick Sound : not uncommon. 



21. Psammobia florida. In Lerwick Sound : not uncommon. 

 Swansea, Sept. 1841. 



XXI. — Brief and Practical Instructions for the Breeding of 

 Salmon and other Fish artificially. By Sir Francis A. 

 Mackenzie, Bart. 



In the autumn of 1840, having chosen a brook flowing ra- 

 pidly into the river Ewe, a hollow spot adjoining to it was 

 selected and cleared out, of the following dimensions : length 

 23 yards, breadth from 12 to 18 feet; and all large stones ha- 

 ving been taken away, the bottom was covered 1 foot thick 

 with coarse sand and small gravel, the largest stones not ex- 

 ceeding the size of a walnut. A stream from the brook was 

 then led into this hollow, so as to form a pool of about 8 inches 

 in depth at the upper and 3 feet at the lower end, thus giving 

 it one uniform gentle current over the whole pool ; whilst the 

 supply of water was so regulated by a sluice as to have the 

 same depth at all times, and a strong stone wall excluded all 

 eels or trout, so destructive both to spawn and fry. 



On the 13th of November, four pair of salmon, male and 

 female, were taken by net from the Ewe, and carefully placed 

 in the pool ; on the 18th they showed a disposition to spawn, 

 but on the 20th the whole were carried away by some ill-dis- 



