ZOOLOGY AND BOTANY, MICROSCOPY. ETC. G25 



(3) Reproductive organs developed on the upper side of each filament- 

 zone, forming, when ripe, (often only rudimentary) intermediate bauds 

 between the successive interstices formed by the filament-zones. (Type : 

 P. variegata.) 



The comparatively rare oogonia and antheridia are arranged in the 

 same way as the much more frequent tetrasporangia. Several now species 

 are described belonging to each of the above groups. 



Formation of Cysts in Ulothrix.* — M. E. de Wildeman records the 

 formation of exogenous cysts in the sense in which the term is used by Gay,! 

 in several species of Ulothrix. They appear to be formed under conditions 

 of insufficient suj)ply of moisture or nutriment, and constitute probably the 

 only mode of propagation when the plant grows on the trunks of trees, on 

 moist soil, or otherwise exposed to the air. 



Allogonium.| — Dr. A. Hansgirg claims priority for this generic name, 

 including under it five species of Ulotrichacese, hitherto placed in different 

 genera. He now sinks his own genus Chroodactylon as a section of 

 Allogonium. 



New Parasites of Daphni8e.§— M. E. Moniez has found a new species 

 of Amoehidium (which he calls A. cienhowskianum) on several Daphnise at 

 Lille ; a study of its characters has shown him that Amoehidium is a para- 

 sitic form of the free genus Baphidium, one of the PalmellaceaB ; another 

 new species is called A. crassum, and it is an endoparasite, having been 

 taken from the intestine of Eurycercus lamellatus. The name of Chytridhoema 

 cladocerarum has been given to a parasite of Simocephalus retulus and 

 Acroprus leucocephalus ; its zoospores are extraordinarily abundant in the 

 blood, and are almost 3 /x at their greatest width ; its contents vary con- 

 siderably, and it appears to recall at one and the same time the Chytridise, 

 01j)idiefB, and Ancylistese. 



Another type of parasite, which must be placed with the Gymnoascese, 

 is Botellus ; B. hjpicus is a parasite of Daphnia reticulata, in the genital 

 organs of which it is developed ; B. parvus is found in Cyprls vidua. The 

 psorosperms or spores of fungi noted by various observers in the circu- 

 lating apparatus of Daphnids have been investigated by the author, who 

 groups them as (1) Microsporidia ohtusa from Simocephalus retulus and 

 Daphnia reticulata ; M. ovata from S. retulus and Chydorus sphsericus ; M. 

 elongata from S. retulus; M. acuta and M. incur vata from Daphnia pulex. 



Mountain Algae. || — Dr. A. Hansgirg compares the algal flora of the 

 mountain-region of Bohemia with that of the lowlands and plains. A large 

 number of the species comprising the latter occur also in the former region, 

 chiefly cosmopolitan species ; but there are also many peculiar to the higher 

 altitudes, though the total number of species is smaller. The moist silurian 

 limestone rocks in the neighbourhood of Prague have a peculiar algal flora, 

 several very rare species, belonging especially to the Phycoehromaceae, being 

 found in the clear springs and brooks in this region ; and a different flora 

 is again characteristic of the primary mountains of Bohemia. The florae 

 of the carboniferous, cretaceous, and tertiary formations of Bohemia are 

 less rich and more uniform, but include some rare species of Phycoehromaceae. 

 A list is given of some species belonging to all classes found only at great 

 altitudes in the Eiesengebirge. 



* CR. Soc. R. Bot. Belg., 1887, pp. 52-5. f See this Journal, ante, p. 277. 



X Hedwigia, xxvi. (1887) pp. 21-3. § Comptes Eendus, civ. (1887) pp. 183-5. 



II Oesttrr. Bot. Zeitschr., xxxvu. (1887) pp. 13-17, 54-8, 97-101. 



