ftf) Journal of Entomologi,- and Zoology 



system. There are no concentrations any place to form a ganglion ; 

 tilt' chief nervous system lies vent rally. Two longitudinal nerve 

 tubes or nerve hands are described running the length ot the body. 

 The nerve strands may give the appearance of tubes due to shrink- 

 age; epithelial cells seem to compose it and the tissue does not look 

 like nervous tissue. These longitudinal tubes or nerves may be 

 some sort of sense organ. 



Cori, 1890, adds nothing to the general knowledge of the nerv- 

 ous system. 



Torrey, lUll, in P. iHirilica gives a partial description of the 

 nervous system as like that of P. architecta with the exception that 

 "The two longitudinal cords which are of e.xceedingly unequal 

 length, instead of continuing in the nerve ring of the lopophore, are 

 continuous across the median line at the level of the median mass 

 of ganglion cells. The loop thus formed is closely applied to the 

 latter and touches the lophophore nerve on each side of the rectum, 

 apparently without fusing at either point." I have found no such 

 condition in several good series of well stained Ph(ir<))ns ixicitiva. 

 Either this was an individual difference or Torrey's material was 

 poorly fixed. 



Schultz, 1903, discusses the regeneration of the central nervous 

 system. 



De Selys-Longchamps, 1907, described the circular nerve ring 

 and ganglion and the lateral nerve of Caldwell on the left. 



Pixel], 1912, discusses two new species of Phoronida. 



In Phoronis vanconverensis, there is the usual ring of nervous 

 tissue at the l)ase of the lophophore; from it five nerves continue up 

 the tentacles. Across the dorsal surface in front of the anus is a 

 large ganglionic mass composed of fibers and cells with large nuclei. 

 This tissue is everywhere in intimate relation with the inner ends 

 of the epithelial cells. In some sections two small lateral nerve 

 cords ran along the right and left sides of the body close to the 

 l)oint of attachment of the lateral me.senteries and projected into 

 the basement membrane. He describes these as, "punctated tis- 

 sue." They are very short. Nervous tissue was found in the 

 center of the pit at the proximal end of the body and also along the 

 /ilimentary canal on the outer side of the epithelium especially 

 marked in the region of the oesophagus opposite the nerve ring. 

 Gilchrist, so he says, suggests this patch as an organ of taste. 



Phoronapsiii hamesi has a similar condition of the nerve ring 

 luit the ring is narrower and more elongated than in PliorouiK. A 

 conspicuous nerve cord extends down the left side. In the neph- 

 ridial region it is sejiarated from the ei)ith('lium and embedded in 

 the basement membrane; after i)assing inti'rnally to the nei)hridial 

 duct it turns outwards and rejoins the epithelium a little to the 

 oral side of the lateral mesentery. From here it extends as a con- 



