studies oil iiKiriiu! Ostraiods 707 



fig. 7 this antenna has a very powerful bristle of this kind. A very eareful investigation of the 

 specimens at my disposal showed that there was no such bristle in the species dealt with by me 

 above. Of the other characters only the length of the shell and the rod-shaped organ in the 

 female are mentioned by V. VAvRA; these statements do not permit of a certain identification. 



The name C. spinmistris Claus is also fomad mentioned in the following places in literature: 

 C. Olai s, 1893, p. 286 and 1894, p. 2; G. VV. MlLLEH, 1893, p. 376; E. Graeffe, 1900, 

 p. 34; G. S. Brady, 1902 a, p. 199 (= the same author, 1903, pp. 338 and 339 and A. M. NORMAN, 

 1905, p. 155); S. Lo BUNCO, 1903, pp.120, 122, 124, 125, 128, 148, 150, 199, 235 and 

 1904, p. 45 (with a very superficial drawing); P. T. Cleve, 1904, p. 370; B. Ka.jdiz, 1912, 

 pp. 938 and 939 and Th. Scott, 1912 a, p. 587. G. W. MtlLLER, 1893, only deals with larvae, 

 and it is impossible to decide their identity with certainty by means of the descriptions he gives. 

 The rest of these statements have neither descriptions nor verificatory figures. Because of this 

 and of the uncertainty attached to this species it seemed to me best not to include these state- 

 ments in the list of synonyms given above. 



L. SCHWEIGER in his treatise of 1912 points out (p. 267) ,,eine MiBbildung" Hod-shaped organ. 

 with regard to the rod-shaped organ in foiu- females; this abnormality consisted in the 

 fact that this organ was furnished with two fine distal points. The females of the 

 above-mentioned species investigated by me were characterized, as is seen above, by two 

 similar points on this organ. 



Special attention ought perhaps to be drawn to the curious fact that in the plankton .1 quesunn of the 

 samples brought home by the S. A. E. the males of this species were in an enormous majority. °'^'^''^"sy <'f repro- 

 Only four females were found, three at station 19 and one at station 45. At station 33 there 

 were found no less than 22 males of this species and not a single female ! In other species the 

 males and females were in most cases almost equally numerous or else the latter predominated. 

 How are we to explain this curious state of affairs'? 



Habitat: — A 1 1 a n t i c (J c e a ii : 



S. A. E., PI. station 19, lat. 36" 13' N., long. 17" 16' W.; at the surface; 4. XL 1901; 

 temperature, 18,5" C: 3 mature females and 3 juvenes; R. M. S. 296. S. A. E., PI. station 23, 

 lat. 34" 2' N., long. 18" 21' W.; at the surface; 5. XI. 1901; temperature, 20,1" C: 1 mature 

 male; R. M. S. 297. S. A. E., PI. station 26, lat. 32" 21' N., long. 19" 8' W.; at the surface; 

 6. XI. 1901; temperature, 20,5" C: 1 mature male; R. M. S. 298. S. A. E., PI. station 33, hit. 

 280 21' N., long. 200 42' W.; at the surface; 8. XL 1901; temperature, 21,5" C: 22 mature males; 

 R. M. S. 299. S. A. E., PI. station 45, lat. 22" 8' N., kmg. 22" 52'\V.; at the surface; 

 11. XL 1901; temperature, 23,3" C. : 6 mature males and 1 mature female; R. M. S. 

 300. S. A. E., PI. station 53, lat. 18" 10' N., long. 24" 28' \V.; at the surface; 13. XL 

 1901; temperature, 23,8" C: 1 mature male. S. A. E., PL station 83. lat. 1" 31' N., k)ng. 29" 7' W.; 

 at the surface; 22. XL 1901; temperature, 26,8" C: 1 mature male; R. M. S. 301. S. A. E., 

 PI. station 95, lat. 3" 7' 8., long. 30" 54' W.; at the surface; 25. XL 1901; temperature, 26,3" C: 

 2 mature males; R. M. S. 302. S. A. E., PI. station 127, lat. 20" 35' S., long. 37" 26' W.; 

 at the surface; 4. XI L 1901; temperature, about 25" C: 2 mature males; R. M. S. 303, 



