L
Ü
l.
Fresh or brackish water. Lewes, March 1851, W. Sm. Northfleet, Kent,
Mr. Shadbolt, Feb. 1852.
Plate IX. 70.
16. Surirella salina, W. Sm. V. ovate-elliptical; alæ obsolete;
canaliculi minute, marginal, numerous, 14 in -OOl". Length -0005"
to -0018". v.v.
W. Sm. Ann. 2nd Ser. vol. vii. pi. iii. 6.
Marine or brackish water. Poole Bay, Sept. 1847 ; Hastings, Aug. 1851,
TF. Sm. Timber Pond, W. I. Docks, Feb. 1852, Mr. Shadbolt.
Plate IX. 71.
17. Surirella pinnata, n. sp. V. linear-ovate ; alæ obsolete; canaliculi
large, subdistant, marginal, 15 in -001". Length ‘0006" to
•0013". v.v.
Fresh water. Near Lewes, Jan. and Dec. 1852, TF. Sm.
Plate IX. 72.
18. Surirella angusta, Kütz. F. V. linear truncate; V. linear, acuminate;
alæ obsolete; canaliculi 18 in •OOl". Length "0008" to
•0014". v.v.
Kiitz. Bacill. XXX. 52. ad specim. quæ misit amie. De Brebisson, Jan. 1853.
Fresh water. Lewes, Dee. 1852, TF. Sm.
Supp. Piate XXXI. 260.
19. SurireUa subsalsa, n.sp. F.V. oblong, inflated; V. elliptical-
ovate, striated; striæ 30 in -OOl"; larger extremity rounded, rarely
attenuated; alæ conspicuous ; canaliculi distinct, 8 in -OOl". Length
•0006" to -0016". v.v.
Fresh or brackish water. “ Brooks ” near Lewes, Oct. 1852 ; Newhaven,
Sussex, Dec. 1852, TF. Sm.
Supp. Plate XXXI. 259.
20. SurireUa minuta. De Bréb. V. ovate-elliptical; alæ inconspicuous;
canaliculi marginal, 14 in -OOl". Length •OOOS" to
■0009". v.v.
De Brebisson in Kütz. Sp. Alg. p. 38. ad specimina authentica quæ commu-
nicavit cl. Jenner. \V. Sm. Ann. 2nd Ser. vol. vii. pi. iii. 5.
Fresh water. Corfe Castle, Dec. 1849 ; Lewes, March 1851, TF. Sm..
Plate IX. 73.
G e n u s 1 4 . TRYBLIONELLA, W. Sm.
Frustules free, elliptical or linear; valves plane; aim submarginal or
obsolete; canaliculi inconspicuous, parallel.
This genus differs from Campylodiscus in the more elongated form
of its frustules and the absence of the characteristic bend in its
valves; the canaliculi are also more minute and parallel rather than
radiating. I t agrees with Surirella in the presence of alee, but these
arise from the disc, and are not, as in Surirella, prolongations of the
margin. It is also distinguished by its less conspicuous canaliculi,
and by the frustule never assuming the cuneate form so notable in
Surirella.
1. Tryblionella ScuteUum, n.sp. V. elliptical, marked with a central
depressed line ; canaliculi obsolete ; alæ very short. Length
•0058" to -0085". v.v.
Surirella circumsuta, Bail. Obs. pi. ii. 36. ad specimina quæ communicavit
Prof. Williamson.
Marine. Poole Bay, Nov. 1848, W. Sm. (Hudson River.)
Plate X. 74.
2. Tryblionella gracilis, n. sp. F. V. linear, attenuate towards the
extremities ; V. linear acuminate ; canaliculi parallel, extending to
the central line, 10 to 12 in -OOl"; alæ distinct. Length -0023"
to 0075". v.v.
Fresh and brackish water. Near Lewes, Dec. 1850, and Oct. 1852, W.Sm.
Plate X. 75. Frustule with endochrome. Frontispiece, fig. LXXV.
3. Tryblionella marginata, n. sp. F .V . inflated, extremities obtuse;
V. elliptical, acuminate; canaliculi distinct, marginal, 18 in
•001" ; alæ conspicuous. L e n g th -0011" t o '0026''. v.v.
Fresh and brackish water. Near Lewes, Sept. 1851, WC Sm. Pilling and
Cockerham Marshes, Lancashire, Mr. Johnson. Near Belfast, Dr. Diekie.
Plate X. 76. Ideal section of ftustule, PI. X. fig. s.