F. Cavers . 
116 
ovoid or elongated cell has a close-fitting shell composed of tesselated 
polygonal plates, and either each plate, or only those at the two 
ends of the body, may bear fine silicified outgrowths; there are two 
chromatophores, and the hinder end of the cell contains numerous 
contratile vacuoles, while at the anterior end there is a large non- 
contractile vacuole ; the cysts are also covered with a silicified shell. 
In Microglena (Fig. 5, 19) the vacuole system is further elaborated, 
all the vacuoles being anterior, the smaller contractile vacuoles 
surrounding a large non-contractile vacuole ; there is frequently a 
single basin-like chromatophore; the shell is thin and bears only 
scattered granular outgrowths. In Chrysosphcerella (Fig. 5, 36) the 
cells are united by their hinder ends in a spherical jelly, forming a 
motile Pandorina- like coenobium ; each cell bears on its free outer 
(anterior) end two small cup-like outgrowths from the shell (which 
has the same structure as in Mallomonus) and from each of these 
cups there springs a long flinty spicule; the internal structure of 
the cells resembles that of Microglena, there are two chromatophores, 
each with a stigma. 
Pascher (102) has founded a fourth family of Chromulinales, 
the Cyrtophoraceae, upon three very remarkable epiphytic genera 
which have probably arisen from a type like Chrysopyxis. These 
genera— Pedinella, Palatinella, Cyrtophora (Fig. 5, 33-35) —are 
either sessile or stalked, the body is flattened anteriorly and bears 
a central flagellum surrounded by from six to twenty pseudopodia; 
there is a single basin-shaped chromatophore, but this is more or 
less deeply lobed in front. Pascher (109) has recently described a 
genus ( Lagynion ) which forms a transition between Chrysopyxis 
and the Crytophoraceae; in Lagynion (Fig. 5, 31) the cell is fixed by 
a broad base, and within the collar-like projecting portion of the 
shell the protoplast protrudes short amoeboid pseudopodia around 
the base of the long motionless flagellum or “ rhizopodium.” The 
same writer describes a colourless genus, Heterolagynion (Fig. 5 ,32,) 
evidently derived from Lagynion, and points out that the Cyrto- 
phoraceae show a remarkable parallelism with the Pantostoma- 
tinean genera Pteridomonas and Actinomonas. 
In the Isochrysidales the cells are either free-living or united to 
form colonies of the Volvocine type. Of the nine genera placed here 
(as Hymenomonadaceae) by Senn, the unicellular genus Wysotzkia 
should be transferred to the Phaeochrysidales (Cryptomonads), and 
the palmelloid genera Phceocystis (Ostenfeld 96), and Ncegeliella 
(Correns, 27) to the Phaeocapsaceae; in these three genera the 
two flagella are inserted laterally, and while Wysotzkia is clearly 
related to the simpler Cryptomonads, especially to the two recently 
discovered genera Protochrysis and Cryptochrysis, it seems equally 
obvious that the affinities of Phceocystis and Ncegeliella are with the 
lower Phaeophyceae, hence they should be removed from the Brown 
Flagellata altogether. In the simplest lsochrysid genus, Hymeno- 
monas (Fig. 6, /), the cell has a firm thick periplast, though the 
anterior portion of the protoplast is naked and capable of putting 
forth pseudopodia. In this order, evolution appears to have taken 
place in two directions, one leading to epiphytic forms recalling 
Chrysopyxis and its allies among the Chromulinales, the other to 
motile colonies. Of the epiphytic forms, Stylochrysalis (Fig. 6, 3), 
