68 



Dryopteris Lloydii n. sp. 



Diagnosis. — Outline of whole frond unknown; pinnae rather 

 thick and firm in texture, narrowly linear, acute, cut nearly to 

 the rachis into numerous alternate, deltoid, obtuse pinnules; 

 fertile pinnae slightly smaller that the sterile pinnae; nervation 

 consisting of a rather strong slightly flexuose midvein and some 

 three or four pairs of slender, once-forked veins; fertile pinnae 

 small; sori relatively very large, 3 or 4 to each pinnule and nearly 

 covering it; indusium centrally peltate; sporangia evidently of 

 large size, producing pits in the leaf substance, the pits disposed 

 more or less clearly in three circles, the outer circle with about 

 15, the middle circle with 7 or 8 and the inner a cluster of about 5. 



Types. — U. S. National Museum, Nos. 34,970, 34,971, 34,972. 



Locality. — Near mouth of Judith River, Fergus County, 

 Montana (NW M Sec. 17, T 23 N, R 16 E.). 



Horizon. — ^Judith River formation (Montana group, Creta- 

 ceous). Probably between 30 and 50 feet above the base of the 

 formation. 



This interesting little species is represented by several detached 

 pinnae only, and hence it is impossible to determine the shape 

 of the whole frond, though it was presumably at least bipinnati- 

 fied. There is evidence of slight dimorphism, the fertile pinnae 

 being a little smaller than the sterile ones, and with the pinnules 

 more rounded or obtuse at apex. The nervation, which is 

 obscure on account of the thick substance of the frond, consists 

 of a relatively strong midvein and three or four pairs of once- 

 forking veins at a low angle of emergence. 



The fertile pinnae are 3 or 4 cm. in length and about 5 or 6 mm. 

 in width. They are cut nearly to the rachis into numerous 

 deltoid almost moniliform pinnules which are only about 3 mm. 

 long and 2 mm. broad at the base. The fruit dots are usually 4 

 though sometimes only 3 in number, and are relatively of such 

 large size that they almost completely cover the pinnule; the 

 diameter of the sori is about i mm. ; while the indusium is rarely 

 preserved there is fortunately one which is practically complete 

 showing that it was centrally peltate. When the material is 

 freshly opened each sorus is filled with a carbonaceous mass 

 nearly .5 mm. thick which probably represents the mass of 

 sporangia, though they cannot now be made out. When this 



