PALMELLACER. 17 
“This species, at all events, would appear to be distinct, the cells 
being two to three times smaller than those of T. lubrica and T. gela- 
tinosa."—Hassall. 
This is a doubtful species, which no one but Hassall appears to have 
seen. 
Plate VIL fig. 4. Fragment magnified, after Hassall. 
Genus 11. BOTRYOCOCCUS. Kutz. (1849.) 
Thallus botryoid (or like a bunch of grapes), irregularly 
lobed, mucous, involved in a thin parent membrane (?). Cells 
ovoid or elliptic, united in families, which are densely packed 
within a thin diffluent tegument. 
Represented in Europe by a single species. 
Botryococcus Braunii. Kuz. sp. 892. 
Small, free swimming, green, at length becoming pallid or 
reddish-brown. 
Sizz. Cells -01--0125 mm. (Radbh.). 
Rabh. Alg. iii. 48. Fres. in Abh. Senk. t. ii. f. 27-83. 
Archer Micr. Journ., 1870, p. 88. Kirch. Alg. Schl. p. 111. 
In moor pools, 
Specimens were found by Dr. Moore floating on the surface of Lough 
Bray in long sheets of some yards in length. Mr. Archer remarked 
upon these “that this was not an uncommen alga in moor pools, some- 
times coating submerged sedges, and the like, with a greyish green 
stratum, sometimes, however, suspended in the water in streaks, and 
often isolated. It passes through a red condition. More than once, 
when a single group or family of this alga, from gatherings kept for 
some time in the house, had turned up under a low power of the 
microscope, he had been to some extent deceived by the way in which it 
resembles some radiolarian rhizopod, strange as it may seem. The 
mucous matrix containing the families of cells seems not unfrequently 
to give off rather long, filiform prolongations, which stand out more or 
less radiantly, looking not unlike pseudopodia and these are undoubted 
rhizopoda containing chlorophyll. It might, indeed, be a good example 
of two objects with no affinity in any respect to each other, still super- 
ficially simulating one another.”—Mzero. Journ., 1870, p. 88. 
Plate VII. fig. 2. a, family group ; 6, single family; ¢, undergoing 
segmentation ; d, free mature cells. All magnified 400 diameters. 
Genus 12. APIOCYSTIS. Nég. (1849.) 
Thallus small, vesicular, fixed by a stem-like base. Cells 
globose, scattered, or sometimes 8 disposed in a circle ; contents 
homogenous, or delicately granulose, with a distinct colourless 
vacuole ; tegument thick, dissolving into a homogenous gela- 
tine, cells dividing alternately in all directions. Propagation by 
mobile gonidia, which are globose, and furnished with a pair of 
vibratile cilia. 
This genus consists of a single species, unless the variety linearis of 
Nageli is entitled to rank as specifically distinct. 
D 
