268 Narrikal or Cochin Mud Bank. [No. 12, new seeies. 



circumference of the disk, margin broad and finely striated, inter- 

 nal processes like the last but placed at the angles of the polygon 

 instead of the centre of its sides, Diamr. 1.466"-* 



Genus HALIONYX (Ehr.) 

 Halionyx nonarius. N. S. (J. M.) 



Disk divided into nine compartments or zones by radiating 

 cellular lines, not equidistant, zones formed of parallel rows of 

 cells of which the median alone reaches the centre, a raised border 

 or rim, marked with delicate, radiating moniliform striae which 

 are continued some distance inside the margin : their internal 

 boundary not being very distinctly defined. Diamr. 1*600. " 



Genus ACTINOCYCLUS (Ehr.) 

 Actinocylus moniliformis (Archer.) 

 Genus ASTEROMPH ALUS (Ehr.) 

 Asteromphalus flabellatus ? (Breb., Grew) 

 Genus ACTINOPTYCHUS (Ehr.) 

 Actinoptychus undulatus, (Kutz.) 

 A. quaternarius (Ehr.) 



FAMILY X. — BIDDULPHIEiE. 



Genus BIDDULPHIA (Gray.) 

 P ! ^dulphia Baylii (W. Sm.) 

 Genus ZYGOCEROS (Ehr.) 

 Zygoceros rhombus (Ehr.) 



FAMILY XL— ANGULIFERE^. 

 Genus TRICERATIUM (Ehr.) 

 Triceratium favus, (Ehr.) 



FAMILY XIII. — CHJETOCEREJE. 



Genus, BACTERIASTRUM (Shadbolt.) 

 Bacteriastrum nodulosum (Shadb.) 



FAMILY XIV.— COCCONEIDE^E. 

 Genus COCCONEIS, (Ehr.) 

 Cocconeis crebrestriata (Grev.) 



* Note.— I have left the last 6 species in this Genus for the present, 

 but it is doubtful if they can all be retained there. The two last 

 should probably be included in the next Genus. 



