New Diatoms from Honduras. Described by A. Grunoiv. 167 
Synedra undosa Grun. S. longissima, linearis, in media parte 
tumidula, tumore lanceolato oblongo, cornibns longissimis, linearibus, 
eximie undulatis, ad apieem subclavatis, striis transversis 19 in 
•01 mm. Longit. variabilis, ad ‘85 mm. Tab. CXCIII., Fig. 8, 
a, b. c. 
Common in the Honduras gathering ; Gollmer found it at 
Caraccas, and Huuck in tbe Adriatic Sea near tbe isle of Chesso. 
It is a very distinct species, resembling S. undulata ( S . longis- 
sima Lobarreuski) in outline only, but differs completely by its 
sharp and fine transverse striae. The valves of the latter species 
are irregularly and coarsely punctate, the puncta forming short 
striae near the margin only. 8. undosa seems to be related to a 
Synedra, found by Mr. Hauck near the island of Cherso, which 
has straight horns, and is perhaps an extreme variety of 8 . fulgens, 
to which I have given the name of 8. cornigera ; it attains a 
length of ‘4 mm., the valve is lanceolate ( - 005- - 02 mm. in 
breadth), with longer or shorter horns (• 006- ’008 mm. broad), 
which become wider towards the apices. The striae (14 in • 01 mm.) 
are interrupted by a very narrow median line, and two longi- 
tudinal furrows near the margins, which are more or less con- 
spicuous, PI. CXCIII., Fig. 9. To S. undulata, S. Hennedyana, and 
S. rostrata is allied my S. Frauenfeldii, and which is somewhat 
inefficiently represented in ‘ Verb. Wien zool. bot. Gesellsch.,’ 1862, 
tab. vii., fig. 26. The striae of this species consist of two or three 
coarse dots which become more scattered near the centre and 
apices of the valve. It is distinguished from S. Hennedyana by 
its much shorter and less pronounced horns. PI. CXCIII., Fig. 10, 
a, b, c. 
[In a gathering from the West Indies I found several short 
filaments of ten or twelve frustules, the side views of which were 
exactly like S. Hennedyana. — F. K.] 
Synedra crystallina Kg. var. insignis Grun. (n sp. ?). S. major 
vel maxima, valvis elongatis lineari-lanceolatis, polis paullum in- 
crassatis truncatis, linea media distincta, sulcis longitudinalibus 
marginalibus obsoletis, striis subtiliter punctatis, validis (10-11 
in '01 mm.) in media parte saspe irregularibus, ante apices radi- 
antibus. Longit. ad '8 mm., latit. valvae ' 013- • 019 mm. Tab. 
CXCIII., Fig. 11. 
Pare in the Honduras gathering. 
S. crystallina var. bacillaris Grun. S. major, valvis linearibus, 
polis rotundato obtusis, linea media distincta, sulcis longitudinalibus 
marginalibus obsoletis, striis subtiliter punctatis, validis (8’-9 in 
•001 mm.) in media parte saepe irregularibus, ante apices radianti- 
bus. Longit. ‘32- *36 mm., latit. valvrn • 016- • 017 mm. Tab. 
CXCIII., Fig. 12, a,b,c. 
Honduras, Adriatic Sea, near Lesma. 
