ERRATA. 



Page 1, line 3 — for tridens, read tridentata. 



19, line 29 — for frustules being, read frustules not being. 



35, footnote — for Endosohnia, read Entosolenia. 



31, line 9 — for Orbicula, read nitida. 



43, line 12— for 28 read 27. 



51, last line — for 23, read 26. 



37, footnote — for Endosolenia, read Entosolenia. 



58, Ditto, Ditto Ditto. 



Plate 2_for Fig. 23, read 26. 



