34 FLORA OF LOWER GOAL MEASURES OF MISSOURI. 



region for a goorl diagnosis. I have concluded, therefore, to give only a 

 fignre of a Henry County specimen (No. 4438) in the Lacoe collection, 

 reserving its full description and illustration until the Pottsvnlle flora is 

 specially treated, when this form will he shown to belong to the grou]3 

 represented Idv Ilarhpteris muricata (Schloth.) Zeill., as commonly identified 

 in this country. The plant in hand stands near the latter species. 



Locality. — The form is from Henry County, Missouri, No. 4438, Lacoe 

 collection, U. S. Nat. Mus. The second specimen is from Owens's coal 

 bank, U. S. Nat. Mus., 5437. 



Mariopteris (sp. unv. ?). 



PI. VII, Fig. C. 



The specimen illustrated in PI. VII, Fig. 6, found among the later 

 consignments sent by Dr. Britts, is the only representative in the collections 

 of a form which I have not yet lieen able to definitely correlate with any 

 described species. As will be observed in the photograph, the pinnatifid 

 pinnules; nearly developed into pinnfe, are close, triangular, and notice- 

 ably decurrent. A remarkable feature is the very large proportion of 

 the lower lobes as compared with the few small lobes succeeding, them on 

 the pinnule. In fact, the upper part of the pinniile seems undeveloped. 

 The rachis is finel}" lineate and very narrowly margined. The ner'vation, 

 shown in PL VII, Fig. Qa, is decurrent and fairly distinct. The lamina, 

 slightly thickened, is dull, elevated in ridges between the nerves, and 

 bordered by a very narrow gutter. The general form of the pinnules 

 and the ' features of the lamina are suggestive of Mariopteris nervosa 

 (Brongn.) Zeill., while the form of the lobes and the character of the 

 nervation unite to remind one of the Mariopteris muricata group. Still, 

 the generic reference' of this specimen, which may represent either a new 

 species or an Old World form not understood b}^ me, is considered merely 

 as tentatiA-e. 



iofrt/;Yv/.^Pitcher's qoa\ bank, U. 8. Nat. M^s-, 5666. 



