194 Alexander IV. Evans, 



thallus are involute, so that the ventral surface is seen in profile, 

 the projections give the appearance of irregular solid teeth, these 

 being especially conspicuous at the cucullate apex. The thick- 

 enings have a glassy aspect but their chemical composition has not 

 been investigated. 



The interior cells of the thallus are all thin-walled. Those 

 forming the layer just inside the ventral surface layer are almost 

 isodiametric, averaging about 28x25ju,; those just inside the 

 dorsal layer are a little narrower, averaging about iS/xin width; 

 the remaining cells are about as long as the surface-cells and 

 average 25 /x in width. In cross section, therefore, an abrupt dif- 

 ference in size is apparent when the cells of the ventral surface 

 layer are compared with the others. 



In the material studied by the writer a few male inflorescences 

 are present. They arise directly from the axis and measure about 

 0.45 mm. in length by 0.3 mm. in width. The antheridia numl)er 

 about six, but the other features of the inflorescence are indistinct, 

 owing to the densely crowded projections of the surface-cells. 

 The female inflorescence is still unknown. 



When Stephani first described this peculiar species he stated that 

 the surface was roughened by unequal hyaline cells or by small 

 conical multicellular lamellae. He compared these structures with 

 the outgrowths found in R. spinnJifera, in which a cellular condi- 

 tion is actually present. As a matter of fact the outgrowths of 

 R. granulata are more comparable with the transverse bands of 

 thickening found in R. scahra and A. stolonifera, since they repre- 

 sent nothing more than extreme modifications of the cell-wall. 

 Stephani states further that the thallus is only four cells thick, but 

 the writer suspects that his sections may have been cut from more 

 or less collapsed material. 



25. Riccardia crassicrispa (Steph.) comb. nov. 



Aneura crassicrispa Steph. Kungl. Svenska X'et.-Akad. llandl. 



49'': 6. /. /, c. 191 1. 



Specimens examined: near the mouth of the Rio Fontaine, 

 Tierra del Fuego, 1908, Halle & Skottsherg 70 (U., type of 

 Aneura crassicrispa). Known only from the type locality. 



The plants of this species are fleshy and pale green, turning yel- 



