NEW FORMS OF MARIME DIATOMACE^). 



509 



connection between the segments and the half frustule, which only showed the 

 backs of the segments, I postponed it with other forms, all of which I have now 

 been able to establish as species. I found the present species tolerably frequent 

 in Mr Miles's Corallina gathering, in which detached segments are much com- 

 moner than the entire frustules. 



We shall see, farther on, that a similar structure prevails in a numerous sec- 

 tion of Amphorae, a few of which were described in my last paper on the Glen- 

 shira Sand. 



GROUP VI. 



Amphora. 



The new forms of this genus in these materials are very numerous, since, 

 in addition to almost all those (ten in number) which I had described in the 

 Glenshira Sand, they have yielded about 32 additional undescribed species. And 

 as I have again to describe and figure four of the Glenshira species, which are 

 now better known, there are in all, 36 species of Amphorae to be described and 

 figured. As the whole of the British species figured in the Synopsis of Professor 

 Smith amounted only to eight, it appears that the Glenshira Sand, and the Clyde 

 and Loch Fine dredgings, or the latter alone, without the sand, have yielded a 

 five-fold addition to the British forms of this genus. This may serve to show 

 what stores of undescribed forms are yet to be found in our estuaries ; for all 

 these have been obtained from two localities, namely, Lamlash Bay and the 

 upper part of Loch Fine, just below Inveraray. 



The remarkable group of complex Amphorae, to which I have lately directed 

 attention, and of which the first known example was A. costata, Sm., though the 

 peculiarity of its structure seems to have been overlooked, has now become so 

 large (one-half of the species here described belonging to it) that it is necessary to 

 subdivide the genus. I shall, therefore describe the Amphorae in two sub-groups, 

 viz., A. Simple, and B. Complex Amphorae. 



(Since this paper was read, I have ascertained that two of the Amphorae in 

 the following list of simple species, namely, A. monilifera, and A. spectabilis, be- 

 long to the complex division. The latter is indeed one of the most curious of the 

 complex Amphorae.) 



A. Simple Amphorae. 



63. Amphora turgida, n. sp. 



73. 



Amphora 



, pellucida, n. sp. 



64. 



nana, n. sp. 



74. 



. . . 



lsevis, n. sp. 



65. 



macilenta, n. sp. 



75. 



... 



exigua, n. sp. 



66. 



angusta, n. sp. 



76. 



... 



dubia, n. sp. 



67. 



binodis, n. sp. 



77. 





truncata, n. sp. 



68. 



ventricosa, n. sp. 



78. 



. . . 



oblonga, n. sp. 



69. 



monilifera, n. sp., G 



79. 



• . . 



robusta, n. sp. 



70. 



lineata, n. sp. 



80. 



... 



spectabilis, n. sp 



71. 



Ergadensis, n. sp. 



81. 





Proteus, n. sp. 



72. 



lsevissima, n. sp. 









)L. XXI. PART IV. 







6x 



