143 
a dry pulverulent mass at maturity, and pieducidg on germination 
whorl or cluster of secondary-spores at the apex of the 
BFUTYGe elium 
Entyloma agrees in the free spores, and in the mode of pro- 
duction of the secondary-spores, hut differs in the spore-mass not 
being pulverulent at maturity. 
Urocystis agrees with Tilletia in the spore-mass being dry and 
pulverulent when mature, also in the method of cpm and 
formation of secondary-spores, but differs in the spores being 
produced in groups, the central ones of the group being fertile, 
the peripheral ones sterile. 
The mode of spore-germination is up to the present unknown 
the genus depending on the two remaining features nig 
above—spores free, forming a palton. mass at maturity ; now 
these characters are also common to the eins U: nne di and "the 
means of distinguishing between the two genera in the absence 
of evidence afforded 5 germination, and absence of knowledge 
as to the origin of the pores, turns o n the relatively much larger 
spores in 7'/letia, mises (with one ieccptiehs T. levis) have the 
Ee reticulated or w 
Neovossia was originally separated from Tilletia on some slight 
deren nce in the structure of the epispore. It has recently been 
studied by Brefeld, and although the spore-structure does not 
indicate a generic distinction, this author retains the genus as 
valid; the ‘distinction from Tilletia advanced being a negative 
character—the secondary spores are produced in a tuft at the apex 
of the ee ae as in Tilletia, but do not conjugate in pairs 
as in the las med genus. co attitude is somewhat surprising, 
dirir ‘that Brefeld does not admit of any sexual signifi- 
cance ina junction by a CHEM band of adjoining pairs of 
seco ee 
Key to the species, 
es A. Epispore smooth fig d scl, Z levis, 
Serien B. Epispore warted or echinulate, 
ied produced in the ovar 
20-25 u; epispore with acute pyramidal warts ... 2. T, verrucosa. 
Spores 20-25 "i wp uem aee with minute 
warts Vie i^ 3. T. rotundata. 
Spore a € "n "3 ni : p 16-18, "i : 
epispore very spiet warted .. 4. T, mizta, 
Spores pada nE d under the microscope, 13-16 hi - » 
epispore very m y war 5. T, Ayresii. 
Spores yellow Droit un ie the microscope, 12-15 r; j : 
pispore densely and minutel dea ec T. magnusiana 
ing up i" the epispore, interstices paler . 7. T, rugispora, 
Spores produ lm 
Spores 10-18 a re covered with minute, dark, fl 
pped wa rts formed Lt the breaking u p of the epis 
pore, 8. Z de Baryana, 
Spores Mack bees der ‘the microscope ; $ 'epispore 
minutely papillose 9, T. arctica, 
Spores 35-38 p; — with scattered exceedingly 
minute warts . 10. 7, epiphylla. 
3790 A2 
