G e n u s 2 0 . P INNULARIA, Ehr.
Frustules free, oblong or lanceolate ; valves convex, with a median
line, and nodules at centre and extremities; ribbed or pinnated
with distinct costæ not resolvable into dots.
The species in which the costæ are absent from tbe centre of the valve, as
noticed at page 46, belong to Ehvenberg’s genus Staiiroptera, but the limits
of that genus are too indefinite to permit me to adopt it in the present work.
1. Pinnularia nobilis, Ehr. Y . linear, obtuse, with a central and
terminal inflation ; costæ radiate, not reaching the median line,
contiguous, 12 i n -001". L e n g th -0112" t o -0145". v.s.
Kai'icula nobilis, Kütz. Bacill. iv. 24. Sp. Alg. p. 80. ad specim. quæ misit
amic. De Brebisson. Quek. H. C. pi. xü. 1. a.
Fresh water. Lough Mourne Deposit. Dolgelly Earth. Premnay Peat.
Cantyre Peat. (Nova Scotia. A^ermont, U.S.)
Plate XA'II. 161.
2. Pinnularia major, W. Sm. Y . linear, obtuse, with a central inflation
; costæ as in the last, 14 in -OOl". Length -0072" to -0122".
v.s.
Navicula major, Kütz. Bacill. iv. 19. Navicula viridis, Ehr. Inf. xiii. 16.
Hass. Alg. CÜ. 2.
Fresh water. Lough Mourne Deposit. Premnay Peat. Dolgelly Earth.
Alountains of Aberdeen, Dr. Dickie. Cantyre Peat. Peterhead anil Lough
Island-Eeavey Deposits.
Plate XAHII. 162.
3. Pinnularia viridis, W. Sm. Y . elliptical, attenuated ; costæ as
in the last, 16 in -001". Length -0021" to -0068". v.v.
fi. Costæ parallel, absent from centre of valve.
Aamra/a m nte, Ehr. Inf. xxi. 12. Prit. Anim. iii. 133-136. xviii. 1-6. Kütz.
Bacill. iv. 18, 20. Quek. H. C. xii. 1. b. Navicula viridula, Ehr. Inf.
xiii. 17.
Fresh water: very common. AVforeham, Feb. 1848, W. Sm. Lough
Mourne, Lough Island-Beavey, and Peterhead Deposits. Premnay Peat.
Dolgelly Earth. Cantyre Peat. (New Zealand, Nova Scotia, &c.) Afor. B.
Lewes, Alar. 1852, TF. Sm. Ben M” Dhui, 3Ir. P. Grant.
Plate XAIII. 163. Frustule with endochrome, Frontispiece, fig. CLXIII.
Var./3. PI. XAHII. 163/3.
4. Pinnularia acuminata, n. sp. V. linear, suddenly attenuated
towards the acute extremities; costæ parallel, not reaching the
central line. v.s.
Fresh water. Premnay Peat.
Plate XVIII. 164.
5. Pinnularia oblonga, DA Sm. V. lanceolate, extremities rounded ;
costæ radiate, reaching central line, distant, 11 in ’001". Length
•0042" to -0066". v.v.
Navicula macilenta. Ehr. Inf. xxi. 13. Navicula oblonga, Kiitz. Bacill. iv. 21.
Fresh water; common. Lewes, Oct. 1852, TF. Sm. Belfast, Dr. Dickie.
Peterhead Deposit. Marl, Co. Down.
Plate XVIII. 165. Frustule with endochrome, Frontispiece, fig. CLXV.
6. Pinnularia cardinalis, Ehr. Y . linear, extremities rounded;
costæ radiate, absent from the centre of V., distant, 9 in •OOl".
v.s.
Stauroneis cardinalis, Kütz. Bacill. xxix. 10. Prit. Anim. xv. 72.
Fresh water. Lough Moume Deposit. Cantyre Peat.
Plate XIX. 166.
7. Pinnularia lata, TV. Sm. V. linear, slightly inflated at the centre ;
costæ scarcely radiate, not reaching central line, distant, 7 in •OOl".
Length -0025" to -0044". v.v.
Navicula lata, De Bre'bisson in lit. cum specim. Kütz. Sp. Alg. p. 79.
Fresh water : subalpine. Fell End, Lancashire, at an elevation of 900 feet,
Mr. Johnson, May 1851. Snow Mud, on Ben M' Dhui, at an elevation of
3840 feet. Dr. Dickie.
Plate XAHII. 167. d. outline of ditto in S. D.
8. Pinnularia alpina, n. sp. V. elliptical-lanceolate, obtuse ; costæ
radiate, not reaching central line, distant, 7 to 9 in •OOl". Length
•0038" to -0083". v.s.
Freshwater: subalpine. Mountains of Aberdeen, Dr. Dickie. Ben M'Dhui,
31r. P. Grant. (Falaise, 31. De Brébisson.)
Plate XVIII. 168. b. outline of F. V.