166 



distinguishecl from any other by the shortness of the internodes 

 and, from the unbranched ha bit, has conferred upon this species 

 the name of Constaniinea simplex. It has a short stout, nearly or 

 quite simple.stem, with internodes decidedly shorter than the dia- 

 meter, and rosulate proliferation to form the new laminae. 



As has been shown above, C reniformis P. & R. has been re- 

 moved from this genus and has become Neurocaulon reniforme (P. 

 & R.) Zan. Nearly related to this is probably the doubtful C. Thie- 

 hauti of BoRMET. \w habit and structurc, it is nearer to Neurocaulon 

 reniforme that Constantinea and, while no cystocarps are known as 

 yet, tetrasporangia lack the characteristic paraphyses which are so 

 striking a feature of the nemathecia of what we are inclined to cali 

 the genuine species of Constantinea. In the uncertainty, it is mani- 

 festly unwise to remove it to another genus, but it, as well as N. 

 reniforme, may be considered as having no real claims to be con- 

 sidered in a revision of the genus Constantinea other than as rejectcd 

 species. Constantinea, under the above understanding, forms a com- 

 pact generic type of three species, C. rosa marina (Gmelin) P. & R., 

 C simplex Setchell, and C. sulnilifera sp. nov., and in the foUowing 

 discussion, it will be considered as thus constiluted. 



Constaniinea rosa marina, C. simplex, and C. s'uònlifera agree 

 very well in their general morphology and differ in this widely from • 

 any other, even of the most closely related, generic type. Thcy ali I 

 possess discoid holdfasts, from which arise cylindrical, simple or ir- „^| 

 regularly dichotomously branching stems or stipes which are annu- *^ 



late throusfh the scars of the older eroded laminae. At the summit 



• • 1 



or summits of the stipe or stipes are peltate laminae which are at 



first entire, but later cleft, as a rule, into few to several segments. \ 



New laminae are produced from the stipe growing through the cen- j 



ter of the lamina already present and producing the new lamina at ! 



or near its tip. The internode between the new and the old laminae ] 



is very short, being less than the diameter of the stipe, in C. rosa j 



marina and in C. simplex, giving the rosulate appearance so cha- ' 



racteristic of the forming biade in these two species, but it is longer | 



than the diameter in the case of C. subtilifera, giving to this species j 



a very different and characteristic appearance. In C. simplex, the 



internode remains short throughout the lifc of the plant while in 



