lected ill Cork Harbour were in a living state and in great abundance, and
from tlieir length formed a conspicuous object even to the unassisted eye.
Specimens sent me hy M. He Brebisson are still larger than our native
forms. I have measured frustules from Brest -0318" in length, or nearly
twice as long as the Cork specimens.
Professor Bailey has, as will be seen, constituted a new genus for the reception
of this species ; but I think its general characters are sufficiently near
those o f S y n e d r a to permit its retention in that genus.
60. Synedra deformis, n. sp. Frustules direct; nodule obsolete;
valve linear or linear-elliptical, suddenly constricted towards the
produced and often distorted extremities ; striæ 36 in -OOl".
Length -0005" to -0008". Breadth of valve -0002". v.v.
Fresh water. Lewes, Sussex, March 1853, W .S m .
61. Synedra investiens, n. sp. Frustules direct; nodule obsolete ;
valve linear, slightly attenuated towards the rounded extremities ;
striæ 26 i n -001". Length of F . -0005" t o -0012". Breadth of V.
•00014". v.v.
Marine : thickly covering an E c to c a r p u s . Kirkaldy, Fifeshire, March 1854,
D r . G r e v ille .
62. Synedra tenera, n. sp. Frustules direct, clustered ; V. nearly
linear, or attenuated towards the slightly inflated extremities;
nodule indefinite; striæ 60 in -OOl". Length of F. -0022" to
•0066". Breadth of V. -00005" to -0002". v.v.
Freshwater. Saltcoats, January 1854, Hr. Arao«. New Forest, September
1854 ; Lough Alloa, Co. Cork, J-une 1855 ; near Blarney and near Killaloe,
Co. Cork, July 185.5, W .S m .
In outline not unlike S. d e lic a tis s im a , with which it often occurs intermixed,
hut it is a far smaller form and with more delicate striæ.
63. Gomphonema Naviculoides, n. sp. Stipes quite distinct and
regularly dichotomous ; F. V. nearly linear, truncate ; valves lanceolate,
acute ; nodule central ; extremities equal ; striæ 30 in-OOl".
Length -0013" to -0025". v.v.
Fresh water. Tank of V i c to r ia R e g ia , Botanical Garden, Edinburgh,
August 1853, D r . G r e v ille .
The valve of this interesting species is not to be distinguished from that of
a Navioula, the nodule being almost exactly central. The species has not
occurred to any other collector, and may probably be of foreign origin.
64. Gomphonema capitatum, Ehr. Synop. p. 80.
Var. ft. Upper portion of valve almost linear, elongated, equal to, or slightly
exceeding the lower, v.v.
V.ar. y. V. much attenuated towards both extremities, v.v.
Var./3. W.Sm. Ann.ser. 2. vol. 15. pl. i. 2ft. Var. y. W.Sm. I. c.fig. 2y. Gom-
pkonema'Fusticulus, W. Sm. MSS, Greg. Mic. Journ. vol. iii. p. 37.
Fresh water. Var. ft. Itford near Lewes, November 1853 ; Grasmere,
August 1853, W.Sm. River Spey, July 1854, D r . Gregory. Var. y. Braemar,
August 1854, Hr. Balfour. (Var. ft. Puy du Cliergue, Auvergne, elev.
5576 feet. Var. y. Near Marseilles, May 1854, W. Sm.)
65. Gomphonema ventricosnm, Greg. V. inflated at the centre,
linear, and rounded towards the upper, constricted and obtuse
towards the lower extremity; striæ 30 in -OOl". Length of F.
•0013" to '0018". v.s.
Greg. Mic. Journ. vol. 4. pl. i. 40.
Fresh water. River Spey, July 1854, Hr. Gregory.
66. Gomphonema elongatum, W. Sm. V. inflated at centre, with
a submedian constriction in both divisions ; the upper extremity
capitate, apiculate, or cuneate ; the lower slightly inflated below
the constriction and obtuse ; striæ 24 in -OOl". Length of F.
•0018" to -0045". v.v.
W. Sm. Ann. ser. 2. vol. 15. pl. i. 4. G. Brebissoniil Greg. Mic. Journ. vol. 2.
pl. iv. 18.
Fresh water. Near "Wisbeach, April 1854, Mr. S. Smith ; Barley Lake, Co.
Cork, June 1855, W. Sm. Mull Deposit, Hr. Gregory. (Puy du Cliergue,
Auvergne, June 1854, TV. Sm.)
Gomphonema rostratum, n. sp. Stipes distinct ; V. ovate-
elliptical, produced at the upper extremity into a linear, obtuse
rostrum ; slightly constricted near tlie lower extremity ; striæ 30
in -001". Length of F. -0009" to -0012". Greatest breadth of V.
•00025". v.v.
Fresh water. Barley Lake, Co. Cork, elev. 780 feet, June 1855, TV. Sm.
68. Gomphonema Sarcophagus, Gi-eg. V. linear-ovate, abruptly