ill!Ill

GOMPHONEMA. 273
var. dichotomum. (G. dichotomum IF. St//. ; H.V.H.
f. 19, 20, 21*), plate 7, fig. 310.
Atl., pi. 24,
Less naviculoid, upper apex of valve more obtuse and gently
constricted; stride finer, 12 or 13 in 1 c.d.m. Length, 3'o to 4^5 c.d.m.
Freshwater. England (Comber, Norman). Scotland (W. Sm.). Ireland (W. Sm.l.
Sweden. Finland (Cleve).
var. auritum. (G. auritum A. Braun; H.V.H. Atl., pi. 24,1.
15* ; in Type No. 212), plate 7, fig. 311.
Verv narrowly lanceolate
furnished with two mucous
and less rhomboidal in the ; living state
hyaline horns (see H.V.H. f.
Atl., pi. 24,
Fresh water. Frahan (Delogne). Scotland. Finland, Norway, &c, (Cleve).
G. micropilS Klltz. (Baa, pi. 8, f. 12; H.V.H. Atl., pi. 25, f. 4
and 5; pi. 24, f. 46*; Type No. 219, a form passing into parvulum),
plate 7, fig. 312.
Valve lanceolate, feebly gomphonemoid, with lower moiety regularly
attenuate as far as the apex, more or less subacute ; the upper moiety a little
inflated, with apex very slightly rostrate, capitate.
feebly radiant, 10 in 1 c.d.m. Length, 2-5 to 3 c.d.m.
Striae approximate to raphe,
Fresh water. Rather rare ? Aid. Lig. (DeWild.). Glasgow, Scotland. Fiance (Brebisson. I
bb. The /too apices of valve almost equally obtuse.
G. intricatum Kutz. (Baa, p. 87, pi. 9, f. 4; h.v.h. Atl., pi. 24,
f. 28, 29 : Type
No. 214 [a variety]), plate 7. fig. 313.
Valve narrow, almost linear, length about 6 to 8 times the breadth, a little
inflated at the median portion. Raphe surrounded by a considerable hyaline
zone ; nodules distant from the apices. Striae feebly radiant, 8 to 10 in 1 c.d.m.
Length, about 4 to 6 c.d.m.
Fresh water. Ard. Lieg. (
De Wild.!. England (Comber, Norman). Ireland (O'Meara).
var. vibrio. (G. vibrio Ehr., Verb., p. 128, pi. 2, i., fig. 40 ;
Atl., pi. 24, f. 26 and 27*; Type No. 216), plate 29, fig. 812.
H.V.H.
Exactly resembles the previous form, from which it only differs in its
size being larger, which attains 9 c.d.m., and by the stauroneiform hyaline
area being much more distinct.
Quiet fresh water. England (Normani, Ireland (O'Meara). France, Prussia, and probably
others.
G. angUStatum KlltZ. (Baa, p. 83, pi. 8, f. 4 ; G. commune Rab. ;
H.V.H. Atl., pi. 24, f. 48, 49, 50*; Type No. 2.5), plate 7, fig. 314.
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