528 PROFESSOR GREGORY ON 



marked with small granules. Striation transverse, fine ; number of striae not 

 counted, but they are much finer than in A. pusilla. The detached segments are 

 not yet known ; but, as seen in fig. 98, the segments appear to be very narrow, and 

 linear in form, the dorsal margin being hardly convex. The inner curve-lines and 

 nodules are obscure. These characters, as well as the finer striations, the finer 

 granulation of the bars in fig. 100 b, and the peculiar form of the middle space 

 in fig. 100, sufficiently distinguish it from A. pusilla, the only form it resembles. 

 This species occurs in the same Loch Fine dredging with those which imme- 

 diately precede. 



The numerous examples here given of complex Amphorae, to which, as we 

 have seen, two have been added from the simple group, prove that this group of 

 forms is by no means a small one, since so many have been obtained in one lo- 

 cality. It is worthy of remark, that the same dredging, which has yielded 

 at least 12 or 13 of the forms just described, also contains A. costata, Sm., 

 already alluded to as the first Complex Amphora ever figured in this country, 

 though the peculiarities of its structure had not been fully appreciated. In fact, 

 as we have seen A . Grevilliana, A . complexa and A . fascata to form a smaller group 

 of closely allied species, so A. granidata, A. proboscidea >,, and A. cymbifera also 

 form another such group, to which A. costata also belongs. It would almost seem 

 as if the locality were favourable to these complex forms ; for on the waters of the 

 Clyde the whole of them occur. We have also in these waters four Amphiprorce, 

 with the remarkable additions of plates lying on the valves, namely, Apr. pusilla, 

 Apr. lepidopterce, Apr. plicata, and Apr. maxima; and lastly we have the doubtfully 

 named Apr. complexa, which exhibits the same complex structure in its middle 

 portion as we find in so many species of Amphora, that, namely, of segments 

 packed together, and converging on the ends, like those of an orange or melon. 

 But we must also remember that the same locality is equally rich in new forms 

 of simple Amphorae. 



GROUP VII. 



Miscellaneous. 



Tn this last group I shall describe a few forms of genera not yet named in this 

 communication, and among them one or two whose real nature is doubtful. 

 These are : — 



101. Navicula (?) Libellus, n. sp. 



102. Nitzschia (?) panduriformis, n. sp, 



103. Nitzschia distans, n. sp., G. 



104. ••• hyalina, n. sp. 



105. Pleurosigma (?) reversutn, n. sp. 



and, as an Appendix, 



109. Creswellia Turris, n. sp., (Arnott) 



106. Sceptroneis Caduceus. Ehr. 



107. Synedra undulata, Greg. 

 Toxarium undulatum, Bail. 



108. Synedra Hennedyana, n. sp. (?) 



