130 



K. OKAMURA. 



chain differs somewhat from the lowest with respect to the angular flexure 

 and the gentle curvature of antapical horns, especially of the left one. 

 Should the lowest individual (i.e., the lowest in the figure and the one 

 having longest apical horn) be set free, it may readily be taken for a form 

 of other species of Ccrathtm. It is in some measure distinguished from 

 related forms by a stouter form of body and horns. The apical horn 

 shows low insignificant lists along its ridges. 



Loc. in Japan : Prov. Tosa. 



Other known loc. : Caribbean Sea ; Bahamas ; Indian Ocean. 



21. C. VOlans Cleve. (Pl. IV., fig. 18). 



Cleve, 1900 a, p. 15 ; Pl. VII., fig. 4. — Ostf. and Schm., 1901, p. 168 ; 

 fig. 21. 



I have referred all the forms illustrated in figs. 18, a-d, to this species, 

 considering that shown in fig. e to be typical, on account of the angular 

 flexure of antapical horns. If I am right in this identification, it is to be 

 considered that the individuals are subject to variation in some measure with 

 respect to the direction and curvature of antapical horns, figs, a and d 

 representing two extreme cases. Fig. a much resembles C. patent issimiim 

 with which :this species agrees in the smallness of body. It may be 

 doubted if the original of fig. d is referable to the present species, on 

 account of the great approach made by the antapical horns toward the 

 apical one. 



Loc. in Japan : Provs. of Böshyü and Tosa. 

 Other known loc. : Atlantic and Indian Oceans. 



22. C. patentissimum Ostf. and Schm. (PI. III., fig. 2). 

 Ostf. and Schm., 1901, p. 168 ; fig. 22. 



Loc. in Japan : Provs. of Böshyü and Tosa. 

 Other known loc. : Red Sea. 



23. C. hirundinella f. piburgense Zederb. (Pl. IV., fig. 24). 

 Zederb., 1904, p. 5 ; T. V., figs. 8-12. 



The specimen figured measures : length of apical horn 0.08 mm. ; 

 length of the right, of the left and of the middle antapical horns, 



