NEW FORMS OF MARINE DIATOMACE. 511 
run nearly parallel to the outer margin of the valve, but are less curved, and 
generally obscure. Strize transverse, obscure, about 30 in 0-001’. 
This very curious little form occurs by no means unfrequently in Professor ALL- 
MAN’s dredging from Lamlash Bay, and more sparingly in the Loch Fine dredg- 
ing alluded to under A. twrgida. The resemblance of the detached valves to Eu- 
notia Camelus has been mentioned. The entire frustule also resembles amini a- 
ture of A. angularis, Greg., figured by me in my first paper on the Glenshira Sand. 
(See Micr. Jour., vol. iii., pl. iv., fig. 6.) But besides the much smaller size of 
A. binodis, the expansions in’A. angularis are more angular; indeed, the figure. 
represents them less so than they are; and the striation of A. angularis is not 
only distinct, but very much coarser, so that the whole aspect of the two forms 
is different. 
68. Amphora ventricosa, n. sp. Pl. XIL., fig. 68 and 686. Form linear-lan- 
ceolate, with obtuse apices, more or less expanded in the middle. Valves long, 
very slender, arcuate, with acute ends, marked with somewhat coarse transverse 
strie. Length from 0:0023" to 00035’; greatest breadth at the expansion in the 
middle 0-005’ to 0-008". Inner lines generally obscure, but in some cases well 
seen. They arise from the inner angle of the valve, pass rapidly across, and, as 
shown in fie. 68 6, sometimes extend beyond the outer margin; then suddenly 
_ bend inwards to meet the obscure nodule near the inner margin. Rectangular 
middle space narrow. Strize strong, about 22 in 0-001” ; conspicuous. 
This pretty and interesting species occurs not unfrequently both in Professor 
Atiman’s dredging from Lamlash Bay, and in the Loch Fine one so often alluded 
to above. The detached valves resemble a very long and slender Cymbella, as 
may be seen in fig. 68, in which the form of the valve is plainly seen on each 
side of the frustule. By focussing, a transverse bar, or elongated nodule, may 
be seen in the middle of the valve; but it is obscured by the strise, when they 
are in focus. 
69. Amphora monilifera, nu. sp. PJ. XIL., fig. 69. Form elliptic, slightly re- 
curved at the apices, which form very short produced extremities. The recurved 
ends of the valves do not meet, and the space between them is filled up by a 
transverse curve-line. Valves arcuate, very convex on dorsal margin, with re- 
curved ends. Nodules on the ventral margin. Between the valves the frustule 
is marked by three to five longitudinal rows of distant round granules, giving 
_ to it a dotted aspect. If there be transverse strie, they are very obscure. Length 
_ from 0:0017’ to 0:0026"; breadth from 0-0008" to 0-0011". 
This pretty and well-marked species is tolerably frequent in the two dredg- 
_ ings mentioned under the last form, but chiefly in that from Lamlash Bay. It 
_ occurs also very sparingly in the Glenshira Sand, as may be seen by referring to 
 mny last plate (Zrans. Mic. Soc., vol. v., pl. i., fig. 53). I had figured, from that 
deposit, an imperfect specimen, which at first I took for an Amphora, but subse- 
a el 
