Sec t . I I . Valves elliptical, e.vtremities rounded.
7. Navicula Liber, n. sp. F. V. oblong; V. elliptical, with rounded
extremities; striæ delicate, 48 in '001"; colour of dry V. purplish.
v.v.
Marine. Coast of Sussex, Sept. 1851, 7IA Sm.
Plate XVI. 133.
S. Navicula firma, Kiitz. V. elliptical, somewhat attenuated towards
the rounded extremities; striæ obscure, 42 in-OOl", parallel. Length
•0025" to -0045". v.v.
fi. Extremities suddenly attenuated ; frustule smaller.
(3. Kiitz. Bacill. xxi. 10.
Freshwater. Near Lewes, Oct. 1851, W.Sm. Near Belfast, Dr. Dicte.
fi. Lough Mourne and Peterhead Deposits. Cantyre Peat. Mari, Co. Down.
(Vermont, U.S., Prof. JVilliamsoii. San Fiore, Italy.)
Plate XVI. 138.
9. Navicula elliptica, n. sp. V. elliptical; striæ distinct, 21 in
•001", interrupted towards the central line. Length -0012" to
■0032". v.v.
Marine. Poole Bay, Sept. 1850 ; Seaford, Sussex, Aug. 1851, W. Sm.
Plate XAAI. 152. A'ar. (Sporangial ?) From Poole Bay, 162 a*. Frustule
with endochrome. Frontispiece, fig. CLII.
10. Navicula ovalis, W. Sm. V. elliptical, occasionally inflated;
striæ distinct, 27 in -OOl", interrupted. Length -0012" to •0020".
v.v.
Navicula elliptica, Kiitz. Bacill. xxx. 55.
Fresh water. Plumpton, Sussex, April 1852, HA Sm. Guildford, Mr.
Capron. Cantyre Peat. Lough Mourne and Peterhead Deposits. Rescobie
and Killicrankie, 3Ir. P. Grant. (Ceylon, Mr. Thwaites, Nov. 1850.)
Plate XAAI. 153.
11. Navicula minutula, n. sp. V. exactly elliptical; striæ faint, SO
in -001". Length -0006" to -0011". v.v.
Fresh water. Near Lewes, Oct. 1852, W. Sm.
Supp. Plate XXXI. 274.
S ect. III. Valves elliptical, extremities acute.
12. Navicula Jennerii, DA Sm. F. V. oblong ; V. twisted, elliptical ;
extremities somewhat acute ; striæ very distinct, 30 in •001", reaching
the central line ; colour of dry valve a pale purple. Length
•0025" to -0068". v.v.
Navicula tumida, Bréb. in Kütz. Sp. Alg. p. 77. ad specimina quæ communicavit
cl. De Brébisson in lit. Sept. 1852.
Marine or brackish water. Rye, Mr. Jenner. Belfast Bay, Aug. 1849,
and Coast of Sussex, frequent, Feb. 1852, W. Sm. Menai Straits, Prof. Williamson,
July 1852.
Plate XVI. 134. b. outUne of F. V.
13. Navicula W e stii, n. sp. F. A'^. oblong; V. straight, elliptical,
acute ; striæ delicate, scarcely reaching the central line, 38 in •OOl" ;
colour of dry valve a dark purple. Length -0032" to •0042". v.v.
Marine; detected by 3Ir. Tuffen West with the last. May 1852. Shoreham
Harbour, Nov. l'852, HA Sm.
Plate XVI. 135.
14. Navicula convexa, n. sp. F. A^. oblong ; V. twisted, acute ;
striæ very distinct, 21 in •OOl", not reaching the central line ; dry
valve colourless. Length -0048" to -0062". v.v.
Marine. Coast of Sussex, Sept. 1851. Harwich, Mr. Shadbolt, May 1852.
Plate XVI. 136. b. outline of F. A'. Frustule with endochrome. Frontispiece,
fig. CXXXAH.
15. Navicula elegans, n. sp. AA elliptical acuminate ; striæ distinct,
24 in •001", waved, radiate, absent around the central nodule.
Length -0020" to -0032". v.v.
Marine or brackish water. Poole Bay, June 1849, W. Sm. Cockerham
Marsh, Lancashire, Mr. Johnson.
Plate XAH. 137.
16. Navicula patula, W. Sm. N. elliptical, somewhat acute ; striæ
delicate, 36 in •OOl", not reaching the central line ; colour of dry
valve purple. Length -0030" to -0040". v.s.