ZOOI-OtiY AND liUTANV, iMlCJiOSUUPY, ETC. 71 



the moor, partly from tlie fragiuents of past plankton-maxima and the 

 remains of undevoured hsh food. In the snnimer of 1911 the same 

 pond was coloured brown tlirough a maximum development of Trache- 

 Jomonas volvocina Ehr. Another pond showed a green colouring from 

 ('/il(im//do))wna.<^ and species of Trai-lielonwnns. E. S. G. 



Green Marine Plankton Alg'a, Meringosphsera. — A. Pas<!HER {Ber. 

 Deutsck. Bot. Gesell., li)17, 35, 170-5, 2 tigs. ; see also Bot. GentralbL, 

 l'.)18, 137, 167). Investigations by the author and by Schiller confirm 

 the author's previous conviction that Meringoq)haera belongs to the 

 Heterokontffi. He gives the following description : — Merinposphaera 

 reproduces itself by four non-motile, endogenously formed autospores. 

 Sometimes it forms endogenous, strongly silicated, two-shelled cysts. 

 Meriiigosphsera is placed in the Heterokont* and not in Chlorophycese, 

 on account of the cell morphology, siliceous membrane, disc-shaped 

 cbromatophores with high carotin content, deficiency of pyrenoids, each 

 of starch, and the formation of endogenous, 2-shelled, siliceous cysts. 

 It is distantly related to Halosplisera, more closely to r>(evdof€trsedron, 

 Gentritr actus, Aurosphsera, EchinosphaerkUion, and perhaps to Acnntho- 

 sphsera. ileriimosphsera is the second of the marine green plankton 

 alga3 to be excluded, like Holosphsera, from ChlorophyceaB. E. S. G. 



Remarks on the Composition of Marine Phytoplankton. — A. 

 Pasc'HER {Biol. (JeniralbL, 191.S, 37, 312-5; see also Bot. Centmlbl., 

 1918, 137, 310-11). Fresh-water phytoplankton is remarkable for its 

 enormous richness in ChlorophyceaB. This character is absent from 

 marine phytoplankton, in which few green species other than Flagellates 

 have been published. Oonjstis occurs in brackish water, but not in the 

 sea. Pelagocystis does not belong to Thlorophycea^. Halosphaera and 

 Meringospihaer-a must be excluded From Chlorophyce^ f<r the following 

 reasons : — Halosphsera has a siliceous membrane, a paucity of pyrenoids 

 in the disc-shaped cbromatophores, a lack of starch, swarm-spores with 

 two unequal cilia, two-shelled siliceous i^planospores, and similar large 

 cysts : Aleringosphxra has a siliceous membrane, disc-shaped cbromato- 

 phores without pyrenoids or starch, and endogenous two-shelled siliceous 

 cysts — all of Avhich characters prevent their inclusion in Chlorophyceae. 

 No marine species of plankton algic belonging properly to Chlorophyceas 

 ha>^ been hitherto recorded. The author places Meringo&plnera and 

 Hidosphsera in Heterokontie, and this group, together with Bacillariaies 

 and Chrysomonadineffi (including Silicoflagelhita; and Coccolitho- 

 phoraceai), in Chrysophyta. Marine phytoplankton, apart from fissile 

 plants, is formed from the two stems of the brown algae, Chrysophyta 

 (Clirysomonadiuffi in a wide sense. Pterospermacese, Bacillariaies, Hetero- 

 kontie) and Pyrrhophyta (Desmomonadales, Cryptomonadales, Dino- 

 flagellata?, Cystoflagellatte). E. S. CI. 



Coccolithophoridse. — H. Lohmann {Vortrag Deutsch. Zool. Ges., 

 I'.n3. I'ord .lahresversannul. Bremen; see also Bot. Gentralljl., 1918, 

 137. 39(1-391). The number of the cilia is without systematic 

 iniportance. A table shows the vertical distribution of tl.e most 



