374 - , . 



Opsunns tau. female. 



X 

 Tautogolahrus adspersun. male. 



One out of thirteen eggs, was impregnated in the single experiment. 

 The rate of clea^-age \yas the same as in the above cross. 



Opsanus tan, female, 



X 

 MenicUa notnta, male. 



Thirteen out of seventeen eggs were impregnated. None of the eggs 

 were polyspermic. The cleavage rate was the same as the Opsanus X 

 Fundulus cross listed above. 



The reciprocals of the above named three crosses with Opsanus tau eggs 

 were attempted but without success. This was doubtless due to tlie unripe 

 condition of the Upsanus tau milt, since I was also unsuccessful in obtaining 

 normals. 



In addition to the crosses detailed above the following were also ef- 

 fected (See Table 9) : 



Fundulus heteroclitus $ X Apeltes quadracus cJ*. 



Tautoga onitis 9 X Tautogolahrus adspersus (^. 



Tautogolahrus adspersus ^ X Tautoga onitis (^. 



Coregonus clupeiformis ? X Argyrosumus artedi cJ'. 



Argyrosomus artedi 9 X Coregonus clupeiformis (^. 



Cristivomer namaycush Q X Salvelinus fontinalis (^. 



