Navicula latiuscula, Kütz. Bacill. v.40. specim. autlien. misit cl. De Brébisson.
Fresh water. Marl, Co. Down.
Plate XVI. 139.
1 7 . Navicula palpebralis, Bréb. V. elliptical, acute; striæ not
reaching central line, 27 in -001". Length -0015" to -0032". v.s.
“Navicula palpebralis,” cl. De Brebisson in lit. Sept. 1852.
Marine. Poole Bay, Aug. 1848. Hull, Hr. R. Harrison.
Supp. Plate XXXI. 273.
S e c t . IV. Valves inflated ; extremities rounded.
18. Navicula obtusa, n. sp. V. elliptical, contracted towards the
rounded extremities ; striæ distinct, 33 in -OOl", not reaching the
central line. v.s.
Freshwater. Eaasay Earth. Marl, Co. Down. Lough Mourne Deposit.
Plate XVI. 140.
19. Navicula Semen, iffiíír. V. oval, contracted towards the rounded
extremities ; striæ distinct, 26 in -OOl". v.s.
Kütz. Bacill. xxviii. 49.
Fresh water. Peterhead Deposit. Lough Mourne Deposit, &c.
Plate XAH. 141.
20. Navicula affinis, Ehr. V. elliptical, contracted, and linear towards
the rounded extremities, v.s.
Ehr. in Kütz. Bacill. xxx. 45 ?
Fresh water. Guildford, Mr. Capron.
Plate XVI. 143.
21. Navicula inflata, Kutz. V. elliptical, inflated; extremities obtuse
; striæ distinct, 28 in ’OOl". v.s.
Kütz. Bacill. iii. 36.
Fresh water. Guildford, Mr. Capron. Peterhead Deposit.
Plate XVII. 158.
22. Navicula gibberula, Kiitz. V. inflated at the centre, linear
towards the rounded extremities, v.v.
Kütz. Bacill. iii. 50*.
Freshwater. Lewes, Feb. 1851, IF. Guildford, Mr. Capro«. Lough
Mourne Deposit. Cantyre Peat. Marl, Co. Down. Dolgelly Earth. Ben
M" Dhui, Mr. P. Grant.
Plate XVII. 160.
S e c t . V. Valves with extremities produced.
23. Navicula ampbirbyucbus, Ehr. V. linear, abruptly contracted
towards the produced extremities ; striæ faint, 48 in •001". Length
•0020" to -0036". v.v.
Kütz. Bacill. xxi. 11.
Freshwater. Lewes, Oct. 1851, IF. Lough Alourne and Peterhead
Deposits. Premnay Peat and Dolgelly Earth. (San Fiore, Italy.)
Plate XAH. 142.
24. Navicula producta, n. sp. V. elliptical, abruptly contracted
towards the produced extremities; striæ faint, 42 in •OOl". v.v.
Fresh water. Lewes, Oct. 1851, IF. Sm. East Shalford, 3Ir. Capron.
Plate XVII. 144.
25. Navicula ambigua, Ehr. \ . elliptical, gradually contracted
towards the obtuse extremities, which are produced ; striæ distinct,
parallel, 36 in -001". Length -0021" to -0033". v.v.
Ehr. in Kütz. Bacill. xxviii. 66.
Freshwater. Lewes, Oct. 1851, HA Sm.
Plate XAH. 149. Frustule with endochrome. Frontispiece, fig. CXLIX.
26. Navicula Ampbisbæna, Bory. Y . elliptical, constricted towards
the extremities, which are rounded and produced; striæ delicate,
40 in -001", not reaching the central line. Length •002l"to -0032".
fi. Extremities slightly produced, obtuse. Length '0017" to -0027". v.v.
Kütz. Bacill. iii. 41 and 42 fi. Ehr. Inf. xiii. 7. Prit. Aiihn. iii. 141.
Hass. Alg. cii. 5.