ON THE DIPLOCHORDA. 337 



12. A. KowALEVSKi.— St. Petersburg, 1807. (' Leuckart's Bericht.,' ' Arcliiv 



f. Naturlescli Jalirg.,' xxxiii.) 

 12a. 11. KouLEE. — ' Internat. Monatsschr. Anat. u. Hist.,' Bd. iii, 1886. 



13. R. Leuckart. — ' Weigniann's Arcliiv,' 1859, 



14. E. Metschnikoff.— ' Zeitsclirift,' Siebold and Kolliker, 1871, pp. 244— 



251. 



15. W. C. McIntosu. — ' " Challenger " Reports,' vol. xxvii, p. 23. 

 15a. I. MiTSUKURi.— ' Journ. Imp. Coll. Sci.,' 189G. 



16. J. MuLLER.— « Archiv fur Anat. und Pliys.,' 184G, pp. 101—104. 



17. T. Morgan.— ' Journ. Morph.,' vol. ix, January, 1894, vol. v, 1891. 



18. A. Schneider.—' Miiller's Archiv,' 18G2, pp. 47—65. 



19. T. Siebold.—' Weigmaun's Archiv,' 1850. 



19a. J. W. Spengel. — ' Fauna v. Flora des Golfes von Neapel,' xviii, 1893, 

 and previous works. 



20. R. Wagener.—' Archiv fiir Anat. und Phys.,' 1847, pp. 202—206. 



21. R. Weldon.— 'Proc. Roy. Soc.,' xlii, p. 146. 



22. E. B. Wilson.—' Quart. Journ. Micr. Sci.,' 1881, pp. 202—218. 



23. A. WiLLEY.— ' Quart. Journ. Micr. Sci.,' 1893. 



24. A.T. Masterman.— ' Proc. Roy. Soc. Edin.,' March, 1896. 



25. A. T. Masterman.— ' Proc. Roy. Soc. Edin.,' June, 1896. 



26. A. T. Masterman.— ' Zool. Anzeig.,' No. 505. 



EXPLANATION OF PLATES 18—22, 



Illustrating Mr. A. T. Mastermaii's paper " On the Diplo- 

 chorda : Part I. The Structure of Actinotrocha.^^ 



List of Abbreviations. 



a.g. Atrial grooves. a. n. Anterior nerve, a. m. n. Anterior median 

 nerve, a. I. n. Anterior lateral nerve. B. c} Pre-oral body-cavity. B. c? 

 Collar body-cavity. B. c? Trunk body-cavity, c, p. Collar-pore. c. n. 

 Collar nephridium. c. n. r. Collar nerve-ring. d. b. v. Dorsal blood-vessel. 

 ». b. V. Ventral blood-vessel. d. n. Dorsal nerve. d. a. Digestive area. 

 ht. Heart, mes. Mesentery between pre-oral and collar cavities, mes . Mes- 

 entery between collar and trunk cavities. m. Mouth. 7ich. Notochord. 

 71. g. Nerve ganglion. «/). Neuropore. «?5. (Esophagus, e.g. Oral grooves. 



