186 Dr Greville’s Descriptions of New Genera 
elongated-oblong ; the wings converging towards the shortly 
truncated ends, gradually constricted in the middle, and 
edged with a border of exceedingly short strive, 16 in 001’, 
no supplementary wing apparent. Length :0055”. (Plate 
IV. fig. 12.) 
Hab.—Curteis Straits, Queensland. 
I feel so much uncertainty regarding this diatom, that its 
present position must be held as merely provisional. The 
general contour is as if it were composed of two broadly 
elliptical lobes. The coarse strive are so very short, that 
they form a mere edging, but showing at the same time a 
radiating direction. 
Amphiprora Jolisiana, n. sp., Grev.—F ront view oblong, 
with perfectly rounded ends and gently constricted sides ; 
wing resembling a narrow border, with a middle row of 
puncta; central portion oblong, with an apparently promi- 
nent edge, and marked with a few faint longitudinal lines. 
Length 0032". (Plate IV. fig 11.) 
Hab.—Curteis Straits, Queensland. 
A beautiful and distinct little species, without any evi- 
dent supplementary wing. The puncta are conspicuous, 
seven or eight in 001"; but I cannot see any striz. 
NAVICULA. 
Navicula diversa, n. sp., Grev.—Oblong, slightly con- 
stricted at the middle, the lobes ovate-elliptical, obtuse at 
the ends; strie moniliform, interrupted by a transverse bar 
composed of two elongated cellules on each side opposite 
the nodule, where an angular space is also left by the striz 
receding from the median line towards the constriction. 
Length about °0025". (Plate IV. fig. 14.) 
Hab.—Curteis Straits, Queensland. 
The most characteristic feature in this small species is 
the transverse bar, which shows an interruption of the striz 
extending to the margin. This bar is composed on each 
side of the nodule of two unequal cellules, the one next the 
nodule being much more elongated than the other. The true 
median line is very fine, while the extra ones are strongly 
marked ; strize conspicuously moniliform, 12 in 001”. 
ea a 
