* 1, 2, 3, growth to Oct. of the same season. 4, 5, 6, 7, larvae possibly of 

 different years. 10, larva of unusual length, Dec. Transformation the follow- 

 ing year. 8, transforming lake lamprey that remained in an aquarium a 

 whole year in the larval stage after reaching full length, transformation ap- 

 parent in late August. 9, transforming lake lamprey from the mud-bank, Dec. 

 June, three larvae taken from the mud-bank showing growth in one year. 

 A, two transforming lake lampreys with contracted circular mouths, T, Aug. 

 One larva of the same length, L, with the characteristic hooded mouth, upper 

 and lower lip. B, about twice natural size. L, larva with hooded mouth. T. 

 transforming lamprey iii a very early stage, Aug. n.c. notochords of decayed 

 lampreys found in the stream in June. The cephalic end points to the right. 



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