180 ' THE MARINE AND FRESH-WATER FISHES. 
SUB-CLASS CYCLOSTOMATA. 
Fam. Petromyzontidae. 
Petromyzon marinus, Zin.—Sea Lamprey. Veryr. Occasionally frequents 
R. Leven, and tributaries of L. Lomond ; ascending from sea in pairs to 
spawn. 
P. fluviatilis, Zin.—River Lamprey ; c. in most streams and lakes. Not 
migratory, and does not spawn in pairs, but promiscuously in groups of 
from 10 to 30 individuals. 
Fam. Myxinidae. 
Myxine glutinosa, Zin.—Hag-fish, Rothesay ; said to be numerous off 
Girvan, and destructive to line-fishes (. B., p. 225). 
SUB-CLASS LEPTOCARDITI. 
Fam. Cirrhostomi. 
Branchiostoma lanceolatum (Pallas)—Lancelet, or Amphioxus; nr. L. 
Cumbrae (R.); bet. L. Cumbrae and Hunterston (Gray). (v. H. B. 
p. 225, Landsborough, etc.) 
prea Gale 
ee 
