170 bulletin: museum of comparative zoology. 



about the areoles. Snture lines with fins. Spines at the angles. Wall areo- 

 late with very large subequal polygons, 13-15 on the circumference at the 

 girdle, 4-6 in each of the pre- and postcingular plates. No pores. 



Length, 29 /x ; diameter, 22 /x. 



Station, 4699. 



Ceratium axiale, sp. nov. 



Plate 4, Fig. 26. 



A medium-sized species of the C tripos group, with apical horn bent to the 

 right, narrowly rounded shoulders and antapicals flexed close to the midbody 

 and subparallel to the apical distally. 



The midbody is rotund. The postmargin is a slightly asymmetrical arc 

 whose radius equals the transdiameter. The antapicals are thus bent an- 

 teriorly very close to the midbody. The right horn is nearer to the mid- 

 body than the left, and bends laterally with more or less concavity on the 

 outer face. It is longer than the left antapical, which is convex laterally and 

 more removed from both the midbody and the apical horn. The distance be- 

 tween the antapicals distally is usually less than a transdiameter, while at the 

 level of the girdle it is 1.25-1.75 transdiameters. The right antapical is 

 sometimes bent beyond the apical, crossing it dorsally. 



Length, 175-285 /x ; transdiameter, 45-60 yx; left antapical, 110-160 /x ; right 

 antapical, 115-200 /x. 



Stations, 4638-4732. 



Ceratium bigelowi, sp. nov. 



Plate 3, Fig. 22. 



An elongated species of the 0. fiirca group, with inflated midbody, whose 

 greatest transdiameter is over twice that at the girdle, long curved apical, and 

 left antapical whose end is curved dorsally and to the left. Apical horn 

 slightly curved to the left. The height of the midbody above the girdle to 

 the base of the apical horn is about four transdiameters at the girdle. Antapex 

 of left horn spinulate. Ventral plate small, oblique, ellipsoidal. Right ant- 

 apical very short, its end scarcely a transdiameter from the girdle. The 

 hypotheca is relatively small, and the inflated part of the epitheca is in the 

 region of the base of the apical plates. 



Length, 900-1030 /*; transdiameter at girdle, 40 /x; greatest transdiameter 

 of epitheca, 80-100 /x. 



Stations, 4728-4730. 



Ceratium claviger, sp. nov. 



Plate 4, Fig. 37. 



A small species related to C ranipes with rounded shoulders and club-shaped, 

 rarely bifurcated ends of the antapicals which are subparallel to the apical. 

 A-pical horn straight, midbody as in C. ranipes. Postindentation slight, if 



