KOFOID AND MICHENER: DINOFLAGELLATES. 289 



Length, excluding fins, 88 p; total, 96 n; dorso- ventral diameter, excluding 

 fins, 70 m, total 90 n. 



Sta. 4671. 



Phalacroma favus, sp. nov. 



A medium sized species somewhat resembling P. mitra Schiitt but differing 

 from it in having the body contracted dorsally as well as ventrally into a stout 

 antapical horn. Length 1.2 dorso-ventral diameters at girdle. Antapical 

 horn 0.25 total length and nearly 2 girdle widths across. Cuneate in dorsal 

 view. Epitheca a low dome. Dorso-ventral diameter at anterior collar less 

 (dorsally) than at posterior. Girdle lists at 40°, wider than girdle, regularly 

 and closely ribbed. No sagittal fin on anterior and dorsal margins. Ventral 

 fin regularly and heavily ribbed with incomplete riblets. Fission spine club- 

 shaped, two girdle widths in length, ventral fin decurrent behind it. Surface 

 coarsely and regularly covered with honeycomb mesh or coarse pits, 24 on 

 the face at the girdle, spinulate near sagittal suture. 



Length, 77 ft; dorso-ventral diameter, 62 p; greatest transverse diameter, 

 excluding fins, 50 yu. 



Sta. 4737. 



Phalacroma fimbriata, sp. nov. 



A very large species with biconical (in dorsal view) body, with high epitheca, 

 wide ribbon-like sagittal fins and very coarsely reticulated body. In dorsal 

 view the body is biconical with apices truncated at suture area. In lateral 

 view the body has rounded ends and flaring girdle. Epitheca very high, its 

 altitude 0.5 dorso-ventral diameter (excluding fins), apex broadly rounded, 

 somewhat nearer ventral than dorsal surface. Hypotheca longer, 0.85 dorso- 

 ventral diameter at girdle (excluding fins), antapex inclined ventrally, broadly 

 rounded. Girdle 0.42 of total length from apex (excluding fins). Ribbed 

 sagittal fins completely encircling the body on either side of suture, higher 

 on right side and posteriorly where it is 2 girdle widths across, and laterally 

 reflexed. Girdle with wide, horizontal, ribbed lists. Surface coarsely reticu- 

 late with large polygons with heavy bounding mesh, 10 behind girdle on right, 

 face, polygonal areas minutely porulate. 



Length, 130 yu, including fins, 152 ix; dorso-ventral diameter, 80 n. 



Sta. 4613. 



Phalacroma gigantea, sp. nov. 



A huge species with delicate theca somewhat resembling P. striata Kofoid, 

 but larger, relatively wider at girdle, and with smaller fins. Body shaped 

 somewhat as in P. striata but more symmetrical posteriorly. Length 0.87 

 to 0.99 dorso-ventral diameter at girdle. Transdiameter exceeding (in some 



