DUBLIN MtCROSCOPlCAt CLUB. 109 



intosh exbibited cross sections of the petioles of Nymplicea alba 

 and N. dentata, and called attention to the differences of structure 

 which obtained in the two. In N. alba the central part of 

 the petiole is occupied by four moderately large lacunae, which 

 are nearly equal in size, one pair being somewhat larger than the 

 other, and surrounding these are a series of smaller lacunae ; the 

 whole of the passages are thickly studded Avith stellate cells. In 

 H. dentata the central part is occupied by two very large lacunae, 

 with a pair of much smaller ones at each end of the septum which 

 separates them; other still smaller lacunae occupy the rest of 

 the circumference ; there are no stellate cells. Mr. Mackintosh 

 hoped to be able to work out these interesting points more in 

 detail, in order to determine if each species has a characteristic 

 structure in its petiole. He also showed sections of the petiole 

 of Villarsia nymphceoides, in which the lacunae are provided with 

 stellate cells somewhat like those of Nymphaea, but devoid of the 

 peculiar tubercles which roughen the surface of the cells of 

 Nymphsea. 



Micrasterias angulosa, Hantzsch, exhibited for the first time in 

 Ireland. — Mr. Archer showed Micrasterias angulosa, Hantzsch, 

 for the first time, though he had long been acquainted with this 

 species ; the specimens were from Co. Westmeath. He showed 

 also a specimen of this species from Professor Eeinsch's collec- 

 tion, gathered in Germany, drawing attention to the complete 

 identy of the examples. 



Mr. Crowe showed, for comparison's sake, several species of 

 Micrasterias taken lately in North "Wales, such as M. rotata, 

 M. denticulata, M. papilifera. — He also showed Actinospharium 

 Eichhornii occurring in the same gathering. 



CosmariumReinschii, n. s., exhibited. — Mr.Archer further showed 

 a Cosmarium which he had no doubt was identical with that re- 

 corded and figured by Prof. Reinsch in his ' Contributiones ad 

 Algologiam et Fungologiam,' t. xviii, f. 4, but not named by that 

 author. This Mr, Archer had also some time known, but it is 

 quite rare ; the present examples were from Co. Westmeath, and 

 he was able to place side by side therewith, under another micro- 

 scope, a specimen found on a slide in Eeinsch's collection. These 

 were perfectly identical, nor could he doubt that the form found 

 in the Eeinschian collection was that the author had in view 

 (loc. cit.), but Mr. Archer thought his figure showed the lateral 

 projections as too angular : they are rather undulately rounded. 

 This species, which seems abundantly distinct, might well stand 

 as Cosmarium Beinschii. 



A Glimpse of a Vampyrella-form. — Mr. Archer spoke of what he 

 would call but a glimpse of a Vampyrella-form and its doings ; 

 though time would not admit of his fully exhibiting some examples 

 of the encysted condition merely (which he had|put up temporarily 

 with a little glycerine) of this so energetic little particle of sar- 

 code, as well as so choice apparently in the selection of its " prey." 

 The active " animal " was of a reddish hue, vacuolate (not unlike 



