8F Canadian Arctic Expedition, 1918-18 
Actinocyclus Ehr. 
Actinocyclus curvatulus Jan. 
Sch. Atlas, Pl. 57, fig. 31. ; 
Found at Stations 23 and 43b. The form which Grunow has called Coscino- 
discus curvatulus var. subocellata in his Diat. F. Jos. Land, Pl. 4, fig. 15, and 
which Rattray in his Rev. Actinocyclus, p. 145, makes A. subocellatus (Grun.) 
Ratt. may or may not be an Actinocyclus, according as its “pseudonodule 
proves to be or not to be genuine; but to overthrow the specific name given by 
Janisch does not commend itself, seeing that the present species has an unmis- 
takable pseudonodule and entirely lacks the distinctive border of Grunow’s 
form. 
Actinocyclus moniliformis Ralfs. , . 
Van Heurck Syn., Pl. 124, fig. 9; W.Sm. Brit. Diat., Pl. 4, fig. 41, misnamed. 
Found in only one dredging, Station 20g. 
Actinoptychus Ehr. 
Actinoptychus undulatus Ehr. 
Sch. Atlas, Pl. 1, figs. 1-4, 6. : 
More or less common throughout the dredgings, markedly so in those from 
Stations 20d, c, g, 23. The only example of this large marine genus found. 
Amphiprora Ehr. 
Amphiprora kryophila Cl. 
Cl. Vega Diat., Pl. 35, fig. 11. 
Found at Station 23, a single specimen. 
Amphiprora obtusa Greg. (in part), see Tropidoneis Stauroptera (Bail.) 
V. A. 
Amphiprora paludosa W. Sm. 
Perag. Diat. France, Pl. 38, figs. 12-15. 
Scarce in three dredgings made at Stations 20b-c, 27s and 41, and the variety 
called punctulata Grun. in Cl. and Grun. Arct. Diat., Pl. 4, fig. 84 also scarce in 
a plankton gathering made at Dolphin and Union strait. 
Amphora Ehr. 
Amphora angusta Greg. var. ventricosa (Greg.) Cl. 
Greg. Diat. Clyde, Pl. 12, fig. 68; see Cl. Nav. Diat., II, p. 135. 
This is what Cleve called A. lanceolata Cl. in his Diat. Spitz., Pl. 23, fig. 2. 
It is somewhat plentiful in dredgings made at Stations 23, 27s, 43b and 43+. 
Amphora angustissima Mann, nom. nov. 
Van Heurck, Belgica Exp., Pl. 5, fig. 5; Perag. Antare. Exp. France, Pl. 2, 
fig. 27, both misnamed. 
This is identical with the two figures given above, both from the Antarctic. 
Van Heurck calls it Amphora angusta var. angustissima and Peragallo Amphora 
lanceolata var. robusta. It is radically distinct from both these species. I have 
given it the earlier of the two supplementary names, which has the advantage 
of suggesting the slight resemblance to A. angusta, to which it stands nearer 
than to A. lanceolata. Several specimens were found in the dredging made at 
Station 43g, between Chantry island and the mainland, Bernard harbour, 
Oct., 1915. 
