ZOOLOGY AND EOTANY^ MICROSCOPY, ETC. 777 



the cMtinous coat of tlie sliell, and striking branclies downwards into 

 the test. Each filament is composed of a number of cells which readily 

 separate from one another, and which may divide internally into secon- 

 dary cells, and then present a remarkable chroococcoid appearance, 

 the cells thus formed being without doubt organs of propagation. In 

 addition to these Hyella produces sporangia resembling those of 

 Dermocarjpa, usually terminal, pyriform, and containing a large number 

 of minute globular spores. 



The organism described by Lagerheim as Codiolum polyrMzum is in 

 reality the sporange of an alga most nearly allied to the SiphonocladaccEe, 

 and named by the present writers Gomontia polyrMza. The sporanges, 

 however, differ from any hitherto known. Gomontia forms green 

 I^atches, especially on dead shells, composed of branched segmented 

 filaments. The sporanges result from a total or partial usually unilateral 

 swelling of one of the cells of the horizontal filaments. From these 

 sporanges proceed two kinds of reproductive bodies, biciliated zoospores 

 which conjugate without germination, and aplanospores. These aplano- 

 spores do not germinate directly, but give birth to bodies resembling the 

 sporanges from which they spring. After remaining for a time in this 

 form, they put out rhizoids into the shell, or divide into from 2 to 8 

 secondary aplanos^Dores. 



Ulothrix and Stichococcus.* — M. E. de "Wildeman agrees with 

 Hansgirg in regarding Ulothrix nitens Men. and TJ. flaccida Ktz. as 

 forms of the same species, but differs from that authority in his view 

 that Stichococcus hacillaris belongs to the cycle of evolution of the same 

 species. Ulothrix undoubtedly has a tendency to break up into isolated 

 cells bearing a strong analogy to those of Stichococcus, but in their 

 filamentous condition there is always a sufficient difference between 

 them. M. de Wildeman has found, associated with U. tenerrima Ktz., 

 another filamentous alga which also has a tendency to break up into 

 isolated cells, and which he identifies with Gloeotila. He suggests that 

 it is this alga which is really another phase of Stichococcus. 



Trentepohlia.| — M. E. de Wildeman defines the characters of several 

 species of this genus, and confirms the observation that species of 

 Trentepohlia enter into the composition of Coccogonium and of other 

 genera of lichens. 



Diatoms from a Trygon.J— Dr. G. B. de Toni has examined the 

 contents of the digestive apparatus of a specimen of Trygon violacea, 

 caught in the Adriatic. Besides a few filaments of Ulothrix implexa and 

 some fragments of an undetermined Cladothrix, he found a large number 

 of diatoms, of which two, Isthmia enervis and Bhabdonema arcuatum, 

 were additions to the diatom-flora of the Adriatic. 



Fungi. 



Luminosity of Fiingi.§ — Mr. W. Phillips enumerates the following 

 species of fungus as certainly known to be luminous : — Agaricus olearius 

 from Europe, A. igneus, Amboyna, A. noctilucens, Manila, A. Gardneri, 

 Brazil, A. lampas, Australia, A. Emerici, Andaman Isles, Polyporus 



* CR. Soc. E. Bot. Belg., 1888, pp. 80-7. Cf. this Journal, ante, p. 632. 



t CR. Soc. R. Bot. Belg., 1888, pp. 140-8. 



t Atti E. Istit. Veaeto Sci., vi. (1888) 5 pp. 



§ Proc. Woolhope Club. See Eev. Mycol., x. (1888; p. 120. 



