18 Journal of Entomology and Zoology 



into two large branches which follow the dorsal line of the epistome. 

 Laterally from the ganglion two other nerve branches go to the 

 epistomal disc. On the ventral surface of the trunk is a medial 

 longitudinal band which is continued into the peduncle. According 

 to Mastermann the mid-dorsal and two lateral epistomal branches 

 have homlogues in Balanglossus and Actinotrocha. 



Rhabdopleura. The account of the structure of Rhabdopleura 

 which is usually given is that of Fowler, 1892. Other accounts 

 which however give little of the nervous system are those of Allman, 

 1869, and Lankester, 1874. 



The central nervous system is represented by a thickening of 

 the ectoderm in the median region of the neck below the nucal pore 

 between the branches of the tentacles. There is a differentiation 

 of nervous tissue much as in Rhabdopleura or Balanoglossus. A 

 black pigment spot is located at the tip of the preoral lobe and may 

 be an eye-spot. 



BIBLIOGRAPHY 

 Fowler, G. H. 



1892. The Morphology of Rhabdopleura normani Allm. Festachrift. 

 zur 70 Geburtst. R. Leuckart's Lepzig. pp. 293-297. pi. 30. 



Harmer, S. F. 



1887. Cephalodiscus. Zool. of H. M. S. Challenger, vo. 22, part 63, pp. 

 39-47, 2 figs, 7 pi. 



Lang, A. 



1890. Zum Verstandni.ss der Organisation von Cephalodiscus dodecalo- 

 phus Mcintosh. Jen. Zeit. f. Nat. vol. 25, pp. 1-12. 



Lankester, E. R. 



1874. Remarks on the Affinities of Rhabdopleura. Q. Jour. mic. sc. vol. 

 14, pp. 77-81. 



18*^4. Contribution to the Knowledge of Rhabdopleura. Q. Jour. mic. sc. 

 vol. 24, pp. 622-647, 5 pi. 



Mastermann, A. T. 



1897. On the Diplochorda. 1. Actinotrocha. 2. Cephalodiscus. Q. Jour, 

 mic. sc. vol. 40, pp. 281-366, pi. 18-26. 



1903. On the Diplochorda. 4. On the central complex of Cephalodiscus. 

 Med. Q. Jour. mic. sc. Ns. vol. 46, pp. 32-33. 



Schepotief, A. 



1908. Cephalodiscus dodecaloptuis. Zool. Jahrb. anat. vol. 25, pp. 405- 

 494. 



