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FREDERICK TILNEY AND LUTHER F. WARREN 



13. Coregonus albus. Hill ('91). 179 In the embryonic state 

 of this species the anlagen of the pineal and parapineal organs 

 both occur. 



14. Caioslomus teres. Hill ('94) 18 found the anlagen of the 

 anterior and posterior epiphysis in embryos of this form. These 

 were almost transversely placed in relation to each other. 



Front 



Hm 



Fig. 56 Transverse section through the end-vesicl'e of the pineal organ in Leu- 

 ciscus rutilus, according to Rabl-Riickhard, 1883. 

 Po., pineal organ; Hm., hemispheres. 



15. Cobitis fossilis and barbatula. Studnicka ('96). 386 The 

 pineal organ in these species is tubular. The distal end forms a 

 large sac which lies beneath the skull. The tractus pinealis is 

 present. 



