18 THE OEDOGONTACEAE 
suffultory cell may be noticeably larger than the other vegeta- 
tive cells, or of the same diameter (Pl. LXIV, figs. 639-640). 
The opening in the wall of the oogonium may be a pore, either 
round and mouth-like, or rimiform, in which case the plant is 
designated as poriferous. An upper part of the oogonium may 
separate from a lower part, forming a lid; such species are 
operculate. The position of the pore as well as that of the 
operculum is quite constant for the species and is of considerable 
diagnostic value. The pore may be superior, supramedian, 
median, inframedian, orinferior. The division of the operculum 
TABLE I. 
Ready reference to illustrations of the kinds of ornamentations of oospore walls 
found in the Oedogoniaceae. It will readily be seen, upon examination of the 
figure, whether it is the middle or outer layer of the oospore wall with 
ornamentations. 



OosPoRE WALL SPECIES PLATE FIGURE 
NVR as 3 Ge oa OS AVOCA CHSTS a= a eee eee LXIII 614 
Areolate:...< 4... Oenarcolatunier a. epee XXVIII 248 
Dentate: 5. ctas 12 Oe NClevcaniurie <hr eee eee XLVI 443 
china bese... 4. Oe. hystricinum........ PNe cole epee ce XLIII 414 
Behinaite:......-: Oey Stniaiy.s GANGAEnS eA oe XLIII 418 
Pitted! jcc ces HOC MOUgan teria ne eee ee ea een a XXIX 260 
Reticulate)...... OeNdvGin OSPOUUI Ee rere eet lee 246 
Rabbedite-tas.aaa|| ati Perialismanr ie Memon ce aia has ee VIII 64 
Ribbed :4; tose le nO UN andi eh aera ae ak VII 52 
Rib lsedeses atc |ROC a PaUGOCOSTQLUII-E ena) ei OOS UL 277 
Rabbed&. 2.5.45. Oenerenulatocostatients.. 9. 2-52 e 14) peeNaVvelelall 240 
Rabbbedse cease OCMCLOS PUT OLCHe emer a ieee ere XLIV 426 
SMOOUIPEE EEC PS RAMU O'S Or trae et Ce ee II 14 
SMOOtM ee seer OenSUpremunten.: .o5- PORE A cr tena. LIX 573 
SCrODIGMate- se RL LOGIN CHS US ee eae ee V 38 
Scrobiculate..... Oe wtupanty, coe Seen eee XXX 261 


may in addition to these positions be supreme or basal (infimus). 
(Pl. LXIV, figs. 624-635). 
The oospore results from the development of the fertilized 
egg and is considered mature upon the formation of a distinct 
wall. It may or may not fill the oogonium and may be unlike 
itin shape. The oospore wall is usually three-layered, although 
occasionally of two layers. The middle or outer layer (it is 
invariably the latter in Bulbochaete) may be smooth or variously 
ornamented (See Table I). The kind of ornamentation is 
widely varied for the different species: pitted, scrobiculate,. 
reticulate, angulate, dentate, areolate, echinate, or longitudinally 
or spirally ribbed. The ribs may be entire, crenulate, toothed, 
