New Genera and Species of Biatomacese. By M. P. Petit. 241 
Epithemia, Breb. 
8. E. ? monilifera (P. Petit). Valves arcbed, covered with 
large moniliform granules, 2 /a 2 in diameter, irregularly disposed, 
often with stout transverse radiant costaB. [The few specimens I 
have seen never bad more than three. — F. K.] Length 72 6 to 
188 /X 4, breadth 15 yn 4. 
Foveaux Strait. PI. XIV., Fig. 10. 
This species very much resembles Schmidt’s Amphora mo- 
nilifera f which he doubtfully refers to A. monilifera of Giregory ; t 
but as neither median line nor central nodule is present, it must 
be placed among the Epithemias. The transverse costae present on 
some individuals confirm this view. On the other hand, the 
characters are not well marked, and the connecting zone is indis- 
tinct, making us doubt the bivalvular nature of the siliceous 
envelope. We ought, perhaps, to consider this organism as much 
a Polycystin as a diatom. [The resemblance to A. monilifera does 
not seem to me very apparent ; it more nearly approaches Grunow’s 
Euodia Frauenfeldii. — F. K.] 
Navicula, Ehr. 
9. N. qusernerensis (Grun.), var. dilatata, P. Petit. This 
variety is distinguished from the type by its larger size and scarcely 
produced apices ; the striae are suhradiant and very delicate ; this 
character, together with the general aspect of the valve, will not 
permit us to consider this form as anything else than a variety of 
Grunow’s species. Length 33 yn, breadth 37 yLt 6. [Query, should 
not these figures he transposed ? — F. K.] Striae, 40 in 25 fju. 
Campbell Island. PI. XV, Fig. 24. 
10. N. Campbellii (P. Petit). Valves lanceolate, with concave 
margins ; extremities cuneiform ; apices rounded ; median line 
straight ; central nodule indistinct, surrounded by a circular blank 
space. Striae distinct, slightly radiant at the centre, parallel towards 
the extremities, reaching median line, excepting at the centre ; no 
longitudinal striae. Length 84 yn 4, breadth 22 /a; 18 to 20 striae 
in 25 fjb. 
Campbell Island. PI. XV, Fig. 23. 
This species is closely allied by its form to N. constricta, 
Grunow, X but differs from that species in the striae reaching the 
median line. 
11. N. biseriata (P. Petit). Valves lanceolate, extremities 
attenuated, apices rounded, median line not reaching the ends of 
the valve, central and terminal nodules distinct. Striae radiant 
interrupted, absent on one side of the central nodule resembling a 
* ‘ Atlas,’ pi. 26, fi^. .S2. 
t ‘ Diatoms of the Clyde.’ 
X ‘Verb.,’ 1860, p. 355, fig. 18. 
