368 Proceedings of the Royal Physical Society. 



Onos tricirratus, captured at Dunbar in 1892. In this species 

 the fourth pair of feet are more rudimentary than in typical 



Caligus. 



Genus (122) Lepeophtheirus, Nordmann, 1832. 

 279. Lepeophtheirus pectoralis (0. F. Miiller). 



1776. Lerncea pectoralis, Miiller, Zool. Dan. Prodr., vol. i. p. 41, 



pi. xxxiii. fig. 7. 

 1850. Lepeophtheirus pectoralis, Baird, Brit. Entom. , p. 275, pi. xxxii. 



fig. 10. 

 1900. ,, „ T. Scott, Eighteenth F. B. Rept., 



pt. iii. p. 150, pi. v. figs. 26-31. 



Hab. — Frequent under the pectoral fins of Plaice, Flounders, 

 and Dabs. 



280. Lepeophtheirus Thompsoni, Baird. 



1850. Lepeophtheirus Thompsoni, Baird, Brit. Entom., p. 278, 



pi. xxxiii. fig. 2. 



1900. „ ,, T. Scott, I. c, p. 152, pi. v. 



figs. 43-45. 



1900. ,, dbscurus, idem, I.e., p. 153, pi. vi. figs. 16-19. 



Hab. — Frequent on the gills of Turbot, Bothus maximus, 

 captured off St Monans. The form I referred doubtfully to 

 L. obscurus, Baird, appears to be identical with L. Thompsoni; 

 it is sometimes common on the gills of the Brill, Bothus 



rhombus. 



281. Lepeophtheirus pollachii, Bassett-Smith. 



1896. Lepeophtheirus pollachii, Bassett-Smith, Ann. and. Mag. Nat. 



Hist. (6), vol. xviii. p. 12, pi. iv. 



fig. 1. 

 1900. ,, ,, T. Scott, op. cit., p. 153, pi. vi. 



figs. 9-15. 



Hab. — Firth of Forth, on the gills of Lythe, Gadus pol- 

 lachius, 8th February 1895; apparently not very rare. 



