ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 259 



the family Spheerococcaceae, then this family includes genera which give 

 examples of three of the four main types of thallus-structure exhibited 

 in the Florideae ; i. e. of all except the simplest, which occurs in the 

 Helminthocladiaceae. This fact illustrates the difficulty of determining 

 the systematic position of a genus of Florideae from a consideration of 

 the structure of the thallus alone. 



Entocladia.* — A fresh- water species of this hitherto exclusively 

 marine genus is described under the name Entocladia gracilis by Dr. A. 

 Hansgirg. It was found growing both endophytically and epiphytically 

 on a species of Cladopliora, germinating in the former case within the 

 cells of the host. It is reproduced either by the direct germination of 

 larger zoospores or by the conjugation of smaller zoogametes. The 

 filaments may either remain distinct or may be associated into a 

 pseudo-parenchymatous mass. 



The genus Entocladia Eeinke was recently assigned by Hansgirg "j" 

 to a systematic position among the Chaetophoracese ; the mode of escape 

 of the zoospores through an orifice in the cell-wall, and the absence of 

 ChsBtophora-like bristles, now incline him to place it rather among the 

 Trentepohliacese, or to refer it to an independent family, the Entocla- 

 diacese, intermediate between this order and the ChsetophoraceaB. 

 Kiitzing's imperfectly described Periplegmatium may possibly be iden- 

 tical with Entocladia ; and Endoclonium Szym., Clidetonema Nowak., and 

 Bolbocoleon Prings. may belong to the same family. Chsetopeltis he now 

 places among the Chsetophoracese rather than the Coleochaetacese. 



Binuclearia.J — Prof. V. B. Wittrock gives the following diagnosis 

 of this new genus of Confervaceae : — Planta serie simplici cellularum 

 formata. Incrementum plantarum bipartitione cellularum intercalare. 

 Cellulse cylindricfe binucleatse ; nuclei bini cellularum vegetantium 

 insequales, unus major, alter minor. Chlorophori in unaquaque cellula 

 singuli, parietales fasciasformes, semiannuliformes. Dissepimenta cellu- 

 larum crassitudine insequali. Zoosporse adhuc ignotse. Propagatio fit 

 cellulis vegetativis in cellulis perdurantibus, membrana incrassata, 

 transformatis. 



The only species, B. tatrana, was found in the Csorber-See in 

 Hungary. The filaments are not enveloped in mucilage ; the vegetative 

 cells are from 6 to 9 /* in diameter, and from the same length to eight 

 times longer. 



Cli8etopeltis.§ — ^Herr M. Mobius finds, attached to Myriophyllum, a 

 new species of Cheetopeltis, differing from Berthold's C. orbicularis both 

 in its smaller size and also in its mode of reproduction, by means of 

 biciliated zoogametes, which conjugate into a zygosperm which is at 

 first l-ciliate, instead of by non-sexual 4-ciliate zoospores. He proposes 

 for the species the name C. minor; and regards the resemblance of 

 Chsetopeltis to Coleochsete as only superficial, constituting in reality, 

 along with Phycopeltis, Mycoidea, and Phyllactidium,\\ a group nearly 

 allied to the ChaBtophoracese. 



* Flora, Ixxi. (1888) pp. 499-507 (1 pi.)- Cf. this Journal, 1880, p. 1023. 

 t Cf. this Journal, 1888, p. 776. 



X Bih. K. Sveusk. Vet.-Akad. HandL, xii. (1887) No. 1, 11 pp. (1 pi.). Cf. this 

 Journal, 1887, p. 441. 



§ Ber. Deutsch. Bot. Gesell., vi. (1888) pp. 242-8 (1 pi.). H Cf. ante, p. 97. 



