NERVOUS SYSTEM OF PHORONIDA . 387 
HAHIEDSHES nial ae ene 
Fig. 3. Section across left side of the junction of the brain and the lophophore 
ganglion. The brain portion is on the right side of the drawing; the lophophore 
thickening is at the left. The beginning of the longitudinal sense organ is near 
the upper part of the sketch. The basement membrane is shown as a dark band. 
x 300. 
Fig. 4 Section of the longitudinal nerve trunk. X 300. 
Fig. 5 Another view of a section of the lophophore thickening. 300. 
Fig. 6 Diagram to illustrate the general form of the nervous system in Phoro- 
nis. The central nervous system is indicated in the central part of the figure. 
The left nerve strand or sense organ is shown on the right of the drawing. The 
tentacles are shown cut off on the right side. On the left side the nerves to the 
tentacle bearing ridge and to the tentacles are shown. The mouth and anal 
openings are not shown. The central nervous system is a mere band of tissue, 
but the view is such that its greatest breadth and thickness are shown. X 70. 
