NEW FORMS OF MARINE DIATOMACE^. 523 



The form figured in my last plate, at fig. 36, as the entire A. Grewlliana, is a 

 new species, to which I now proceed. 



90. A?nphora fasciata, n. sp. PL XIII., fig. 90. Form of entire frustule barrel- 

 shaped, that is, gently convex on the sides, broadly truncate on the ends. The 

 form of the lateral segments, as well as that of the inner curve-lines, is well 

 seen at the sides. Length about 0-005" ; greatest breadth about 0-0023". Be- 

 tween the lateral segments are seven or eight converging bars, separated by 

 very narrow raphes ; these are the backs of other segments. The detached seg- 

 ments are arcuate on the dorsal margin, nearly straight on the ventral margin, 

 with acute ends. They have only one curve-line, bending forward in the 

 middle to the nodule, which is near the ventral margin. Striae about 34 in 

 0001", conspicuous. 



This fine and conspicuous form is not unfrequent in the Glenshira Sand, and 

 occurs also sparingly in Lamlash Bay and in Loch Fine. Unlike the preceding 

 one, it is almost always entire. 



91. Amphora complexa, n. sp. PI. XIII., fig. 91. Form of entire frustule rec- 

 tangular, with rounded extremities. Length about 0-005" ; breadth about 0-0021." 

 Lateral segments narrow, with the dorsal margin straight, except near the apices, 

 where it bends inwards. Inner line strongly curved to the nodule, which lies close 

 to the ventral margin. Between the lateral segments are seven longitudinal con- 

 verging bars, the backs of other segments, which meet on the convex ends, en- 

 tirely filling them up. These bars are separated by raphes, rather broader than in 

 the preceding species. The whole form is marked by transverse striae, which are 

 strong and conspicuous ; about 30 in 0*001". 



This very fine and conspicuous form, which is evidently nearly related to the 

 two which precede it, A. Gr&mlliana and A. fasciata, while yet all these are dis- 

 tinct, as is seen by the figures, occurs, like the others, both in the Glenshira 

 Sand and in Lamlash Bay, and is not very rare. For some time I confounded 

 all these together in the Glenshira Sand, and it was only a careful examination, 

 especially of the detached segments, which showed me that they were really dif- 

 ferent species. 



92. Amphora sulcata, Breb., n. sp. PL XIIL, figs. 92 and 92 b. Form barrel- 

 shaped, rather broad, ends truncate. Length of frustule 0-0041" ; breadth 0-002". 

 Lateral segments broad, arcuate ; inner lines strongly curved, nodule near ventral 

 margin. Between the lateral segments — when viewed in a focus which brings out 

 these segments clearly, as in one of the figures — are seen four or five converging 

 bars. These bars, and all the lines of the lateral segments, are marked by short, 

 transverse striae, the rest of the surface being hyaline. In another focus, the 

 lateral segments and their curve-lines disappear, and the whole width is taken 

 up by seven or eight converging bars, which are now separated by very narrow 

 lines of transverse striae. The whole form is very hyaline and very convex. It 



