THE REPRODUCTIVE SYSTEM OF E. SUPERBA 349 



After I had begun this investigation, a paper by Ruud (1932) appeared on the " Biology 

 of Southern Euphausiidae ", in which Ruud drew attention to the fact that the "ex- 

 ternal sexual characters do not tell us anything about the degree of maturity at which 

 the animal has arrived. This must be ascertained by examining the internal organs, 

 the ovary and the testis." A discussion of his results belongs more appropriately to 

 a second paper now in preparation to which this is the introduction, but I have frequently 

 referred to his work and wish to make full acknowledgement here. I was more fortunate 

 than he in having access to larger collections of material, and consequently could carry 

 my anatomical investigations farther. 



BIBLIOGRAPHY 



Andrews, E. A., 1904. Breeding habits of the Crayfish. Amer. Nat. xxxviii, pp. 165-206, 10 figs. 



Boas, J. E. V., 1883. Studien iiber die Verwandtschaftsbeziehungen der Malakostraken. Gegenbaurs morph. 



Jahrb. Leipzig, viii, pp. 485-579, pis. 21-24. 

 Calman, W. T., 1909. A treatise on Zoology . Edited by E. Ray Lankester. Pt. vii. Appendiculata. 3rd fasc. 



Crustacea., pp. 244-52, 289-90. 

 Chun, C, 1896. Atlantis. Biologische Studien iiber pelagische Organismen. Pt.v. Ueber pelagische Tiefsee- 



Schizopoden. Bibliotheca Zoologica, Stuttgart, vii. Heft 19, pp. 137-90, pis. 8-15. 

 Claus, C, 1868. Ueber die Gattung Cynthia als Geschlechtsform der Mysideengattung Siriella. Zeit. wiss. 



Zool. XVIII, pp. 271-9, pi. I. 

 Eraser, F. C, 1936. On the development and distribution of the young stages of krill (Euphausia superba). 



Discovery Reports, xiv, pp. 1-192. 

 John, D. D., 1936. The southern species of the genus Euphausia. Discovery Reports, xiv, pp. 193-324. 

 KOLTZOFF, N. K., 1906. Die Spermien der Decapoden. Arch. mikr. Anat. Lxxvii, pp. 364-571, 5 pis., 37 figs. 

 KiJKENTHAL, W. and Krumbach, I., 1926-7. Handbuch der Zoologie. III. Pt. i, Euphausiacea, by 



C. Zimmer. Pp. 812-39, figs. 863-902. 

 Meyer, P. F., 1934. Bin Beitrag zur Eiablage der Nordseekrabbe Crangon vulgaris, Fabr. Zool. Anz. cvi, 



PP- 145-57. 4 figs. 

 Raab, F., 1915. Beitrag zur Anatomie und Histologie der Euphausiiden. Arb. zool. Inst. Univ. Wien, xx, 



pp. 125-58, pis. 1-2. 

 Ruud, J. T., 1932. On the biology of southern Euphausiidae. Hvalradets Skrifter, Nr. 2. Oslo, pp. 5-105, 



37 figs- 

 Sars, G. O., 1885. Report on the Schizopoda collected by H.M.S. ' Challenger' during the years 1873-1876. 



Report of the scientific results of the voyage of H.M.S. 'Challenger' during the years 1873-1876, 



XIII, pt. 37, pp. 1-228, pis. 1-38. 

 Zimmer, C, 1913. Untersuchungen iiber den inneren Bau von Euphausia superba Dana. Zoologica, Stuttgart, 



XXVI, pp. 65-128, pis. 8-14. 



