106 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



vertebrae in back bone, no ribs and no developed jaws, no 

 limb-fins ; gills in separate sacks on sides of body. 

 Family Petromyzontim;, Lampreys. 

 Petromyzon fluviatilis, Linn. (Day, vol. II., p. 359, pi. 

 CLXXXIX.). Silver lamprey. 



B.— Series showing the Reproductive Organs, the Spawn, 

 and the young stages in the development and life- 

 history of some fishes from the Egg onwards. 



B. I. Series of Ovaries and Testes (hard and soft roe) . 



1. Ovaries (hard roe) of mature whiting {Gaelics 



merlangus) . 



2. Testes (soft roe) of mature whiting. 



3. Ovaries (hard roe) of mature haddock {Gadus 



ceglefinus). 



4. Testes (soft roe) of mature haddock. 



5. Ovaries of mature herring (Clupea harengus). 



6. Testes of mature herring. 



7. Ovary and oviducts of skate (Baia batis). 



8. Dissection of plaice (Pleuronectes platessa) show- 



ing immature reproductive organs. 



9. Dissection of plaice showing mature repro- 



ductive organs. 



B. II. Series of Mature Ovarian Eggs. 



1. Eggs from the ovary of cod (Gadus morrJiua). 



2. ,, ,, whiting (G. merlangus). 



3. ,, ,, haddock (G. ceglefinus). 



4. ,, ,, hake (Merluccius vulgaris). 



5. ,, ,, grey gurnard (Trigla gur- 



nardus). 



