STILL FOUND IN A LIVING STATE. 863 
suborbicularis, hine tanquam discis duobus coalitis constans, striis 
in centesima linee parte viginti tribus. 
Fossil in the chalk marl of Caltanisetta; recent near Cuxhaven 
and Wismar. Length de — ay". 
51. Navicula (Pinnularia) Entomon. N. testula striata ab utraque 
facie media constricta, apiculo laterali medio nullo, pinnulis (striis ) 
latioribus. 
Recent in the port of Christiania; fossil in the Greek marls. 
Length of the recent 3.'", of the fossil iy!"". 
52. Navicula (Surirella) Folium. N. testula ovata ampla obtusa tur- 
gida parumper compressa, media apertura nulla, pinnis angustis in 
vicesima quarta linez parte 24. 
Recent in the bay of Christiania, and near Tjérn on the coast of 
Gothland. Length 4". 
53. Navicula (Surirella) Gemma, Pl. VIII. fig. 5. N. testula ovato- 
oblonga ampla magna turgida, media apertura nulla, pinnis gracili- 
bus in vicesima quarta linez parte 16. 
Mouth of the Elbe near Cuxhaven. Size J; — j}y!". 
54. Navicula (Pinnularia) norwegica. N. testula a latere lineali an- 
gusta utrinque truncata, a dorso late ovata utrinque acuta, marginis 
limbo anguste striato, area ampla media levi. 
Recent in the port of Christiania. Length .'". 
55. Navicula (Pinnularia) quadrifasciata. N. testula a latere lineari 
angusta truncata, a dorso late ovata utrinque acuta, marginibus limbo 
lato et tenia duplici media longitudinali angustiore striatis. 
Recent in the port of Christiania and near Tjérn; fossil in the 
Greek marls of the chalk. Size 3,!", 
(56. Peridinium pyrophorum. Syn. Per. pyrophorum, 1836. Infus. 
1838. 
Recent near Kiel ; fossil in the flints of Delitzsch, Gravesend, &c. 
Size of the recent 74"". 
57. Podosira nummuloides. Syn. Trochiscia moniliformis, Montagne, 
1837. Melosira hormoides, Mont. MS. 1838. P. corpusculis 
globosis a latere leviter compressis discretis subtilissime puncta- 
tis, ovariis vesiculosis virentibus, pedicello corporis diametro bre- 
viore. 
Recent on Polysiphonia dendroidea, Montagne, near Callao in 
mera. Size ~},!". 
58. Triceratium Favus, Pl. VIII. fig. 10. T. testule lateribus triquetris 
planis aut leviter convexis, angulis obtusioribus superficie cellulis sex 
_ angulis magnis favosa, dorsi angulo medio levi. 
Recent near Cuxhaven ; fossil in the chalk marls of Greece. Dia- 
meter ay". ‘ 
2B2 
