i6F Canadian Arctic Expedition, 1913-18 
Grammatophora Ehr. 
Grammatophora arctica Cl. 
Van Heurck Syn., Pl. 53 bis., fig. 3. 
This is the same as G. antarctica Perag. in Antarct. Exp. France, Pl. 4, 
fig. 12. Found at Stations 20b-c and 23. 
Grammatophora arcuata Ehr. 
Perag. Antarct. Exp. France, Pl. 3, fig. 25; Ehr. Mikro., Pl. 33A, sec. 23, 
fig. 11. 
More or less plentiful in many of the dredgings, especially in those from 
Stations 43a and 43g. 
Grammatophora islandica Ehr. 
Van Heurck Syn., Pl. 53, fig. 7. 
Probably a variety of G. angulosa Ehr. Found at Stations 43a and 438b. 
Grammatophora marina Kiitz. 
Van Heurck Syn., Pl. 53, figs. 9-13. 
Found in the dredging at Station 20g and the plankton haul at Station 12d. 
Grammatophora oceanica Ehr. var. macilenta W. Sm. 
Perag. Diat. France, Pl. 87, fig. 16. 
The markings on this species are exceptionally fine. Found only in the 
dredging from Station 27s. 
Grammatophora subundulata Grun. 
Van Heurck Syn., Pl. 53 bis., fig. 10. 
Placed by some authors as a variety of G. marina. Found only in the dredg- 
ing from Station 48). 
Hantzschia Grun. 
Hantzschia amphioxys (Ehr.) Grun. 
Van Heurck Syn., Pl. 56, figs. 1-6. 
The grounds for separating this from the genus Notzschia, namely its having 
the heavy carinal markings on the same side instead of on opposite sides of the 
two valves of the individual diatom, is insufficient, but it makes for easier 
identification and may therefore be accepted. The present species is generally 
fresh-water but.seems to thrive in marine localities. Found only at Station 41. 
Hyalodiscus Ehr. 
Hyalodiscus hormoides (Mont.) Petit. 
Van Heurck Syn., Pl. 84, figs. 8-4; Grun. Diat. F. Jos. Land, Pl. 5, fig. 32. 
Grunow without apparent justification names his figure var. glacvalis; 
this Gran turns into Lauderia glacialis (Gran Nord. Plankt., p. 23, fig. 23), and’ 
Jorgensen (Jorg. Protist Plankt., Pl. 6, fig. 7) calls it Podosira glacialis. Without 
seeing Gran’s specimens one cannot find a good excuse for making this a Lauderia. 
De Toni (Syl. Alg., p. 1361) says it is what is named Hyalodiscus maximus var. 
arctica in Cl. and Grun. Types No. 1. Found rather abundantly at Stations 
20b-c, 23, 48b and 43c; also what may be a small variety corresponding to the 
figure in Sch. Diat. Nordsee, Pl. 3, fig. 40, there confused with ‘“ Podosira 
hormoides W. Sm.” which is H. scoticus (Kiitz.) Grun. Compare with Van 
Heurck Syn., Pl. 84, figs. 7-8; this small variety occuring at Stations 41 and 43a. 
Hyalodiscus laevis Ehr. 
Ehr. Mikro., Pl. 33, sec. 15, fig. 17. 
Typical specimens were found at Station 48c. 
