NEW FORMS OF MARINE DIATOMACE.E, 505 



narrow, and, but for the absence of apiculi, a miniature of that of Apr. lepidop- 

 tera. (See farther on, fig. 59 b.) Both views, and also the plates, are marked with 

 very fine transverse and parallel striae, which, however, on the F.V. do not ex- 

 tend to the rectangular space between the valves. Striae about 60 in 0-001". 



This pretty little species has occurred only in one of the Loch Fine dredgings, 

 where it is rather scarce. It is remarkable for the occurrence of the lateral 

 plates, which we shall find in several other species, and which perhaps ought to 

 constitute a new genus. But the resemblance to Amphiprora is so great in other 

 points, that I do not think it advisable to separate these species from that genus. 



57. Amphiprora plicata, n. sp. PI. XII, fig. 57. F.V. deeply constricted, with 

 rounded extremities, which are very broad. Inner margin of valves straight. 

 On each valve lies a plate extending from the inner margin of the valve to the 

 nodule; its outer or convex margin being a little incurved in the middle, and 

 bent forward at the ends, to join the inner angles of the valve. The rectangular 

 space joining the two valves is marked with faint vertical lines or folds ; and the 

 valves and lateral plates, as well as the rectangular space, are all marked by fine 

 transverse striae, about 50 in 0001". Length 0-0037"; breadth from nodule to 

 nodule 0-00075", at broadest part 0-0016". Outer margin double. S,V. not yet 

 certainly known. 



This species occurs with the preceding, and is equally scarce. It approaches 

 nearest to Apr. alata, but differs from it in the folds of the middle space, and in 

 the presence of the lateral plates. 



58. Amphiprora elegans, Sm. PI. XII., figs. 58 and 58 b. Form of S.V. linear- 

 lanceolate, ends obtuse. Valve traversed by two longitudinal lines, and marked 

 by fine but distinct transverse striae. Length from 0*0085" to 0-012"; breadth of 

 S.V. about 0-0011". F.V. rectangular, with two longitudinal lines. Striae 44 in 

 0-001", parallel. 



I have figured the S.V. of this fine form, first noticed by Mr Bleakley, be* 

 cause, although described in vol. ii. of the Synopsis, no figure of it has yet appeared. 

 It occurs both in the Glenshira Sand, and in more than one of the dredgings ; but 

 more frequently in one of those from Loch Fine than in any of the others. The 

 valves are, in these deposits, generally detached, so that I have not met with the 

 entire F.V. I am indebted to Mr Roper for an entire specimen, fig. 58 b. 



59. Amphiprora lepidoptera, n. sp. PL XII., figs. 59, 59 b, and 59 c. Form of 

 FV. linear, constricted in the middle, expanded at the apices, which are flatly 

 rounded. Length from 00055" to 0-008" ; breadth of F.V. in the middle 0-0009", 

 near the ends 0-0015". SV. lanceolate, with acute ends, terminating in small api- 

 culi. Central nodule strongly marked ; median lines somewhat curved, meeting 

 in the nodule. Striation fine, parallel, about 48 in 0-001" ; on the F.V. the striae 

 are absent from the middle space. The form of the F.V. with its long slender 

 alae, is very elegant. 



VOL. XXI. PART IV. 6 U 



