1887.] 



Balanoglossus Larva from the Bahamas. 



147 



Fig. 1. 



from one another in the middle line by a considerable interval, and the 

 posterior pair especially leave a considerable part of the blastocoel 

 unoccupied (fig. 2, Bl.). The anterior nearly solid body cavities 



Fig. 2. 



are separated dorsally by a forward process of the posterior cavities ; 

 so that a section so near the middle line as that drawn in fig. 1 does 

 not cut them dorsally at all. 



The anterior region of the body in front of the great transverse 



M 2 



