2 BEITISH CHAEOPHYTA. 



other parts of the membrane, are seen clearly defined. No British 

 species has a reticulate decoration, nor a smooth undecorated 

 surface. 



Distinguishing as granulate the decoration where the granules 

 are all contiguous, and as tuberculate where they are non- 

 contiguous, there appear to be three species having a tuber- 

 culate decoration — Lamjyrothamnium papulosum, C. vulgaris and 

 C. connivens. 



In C. vulgaris this is well marked and serves as a valuable 

 test for distinguishing it from C. contraria, which is often very 

 similar in general appearance. 



In the rest of the Chareae the markings are all granulate and 

 in many cases very similar in their character. It is quite possible 

 that an exhaustive microscopical investigation may reveal 

 sufficiently marked characteristics in the decoration of the 

 membranes as will clearly differentiate each species. 



Genus 1. NITELLOPSIS Hy. 



Chara sub-gen. Tolypellopsis Lbonhaedi in Lotos, XIII, p. 73 (1863). 

 Chara sect. Astephanse Bbaitn in Oolin, Krypt. Fl. Schles. I, p. 402 



(1876). 

 mtellopsis Ht in Bull. Soo. bot. France, XXX YI, p. 397 (1889). 

 Tolypellopsis MiGtrLA Die Characeen, p. 94 (1890). 



Stem and branchlets ecorticate. Stipulodes none. 

 Branchlets with 1-2 nodes, usually producing 1-2 very 

 long bract-cells almost equalling the branchlets in 

 diameter. Bracteoles absent. Oogonia and antheridia 

 arising as direct outgrovpths from the peripheral cells 

 of the branchlet-nodes. Coronula small. The only 

 known species dioecious. 



In the position of the reproductive organs Nitellopsis 

 resembles Lychnothamnus, to which genus the one known 

 species was finally referred by Brarm. Although the principal 

 characters which serve to distinguish it are only vegetative, 

 it is so remarkably distiQct from any other Charophyte that we 

 have followed Hy and Migula in placing it in a separate genus. 

 Braun has suggested an affinity with the large-fruited Charo- 

 phytes of the lower Tertiary series, and there is something 

 simple and archaic-seeming about N. obtusa, which may point 

 to its being a surviving representative of an ancient type. 



