44 THE VOYAGE OF H.M.S. CHALLENGER. 



are clearly developed in specimens of Branchiostoma belcheri (?) of only half the size 

 of this specimen. 



Gonads not fully developed, extending from the first to the twenty-sixth myocomma, 

 and forming two series in the middle. The atrial cavity extends somewhat behind the 

 supposed position of the atrial pore. 



