296 THE POTOMAC OK YOUNGEK MESOZOIC FLORA. 



SAFIN DOPSIS, gen. uov. 



Leaves pinnate, both odd pinnate and abruptly pinnate ; terminal leaves 

 usually more or less united at base ; upper pairs of leaves decurrent, form- 

 ing a wing on the common stem, the wing lessening in width on the pairs 

 in descending ; leaves mostly opposite in pairs, sometimes subopposite ; 

 the lowest pairs lack the wing, and are sometimes short-petioled ; leaves 

 thick, with dense and often glossy epidermis, elliptical or lancet-shaped, 

 with a strong prominent midrib, which extends with slight diminution to the 

 tip of the leaf ; lateral nerves going off at a large angle, and uniting more 

 or less completely near the margin to form a series of arches ; the lateral 

 or primary nerves, as seen on the lower side of the leaves, strong and prom- 

 inent, but on the upper side, owing to the thickness of the leaves, generally 

 indistinct ; the ultimate reticulation is strong, and forms a series of rather 

 large, irregular, polygonal meshes. 



This genus is a very important one in the strata containing the more 

 recent types of plants, especially as seen at the two Brooke localities and at 

 White House. It has furnished an immense number of individuals, forming 

 at these places the predominant fossils. The upper leaves, perhaps owing 

 to the presence of the wings, seem to have been very persistent. It is 

 probable that, normally in all cases, the lowest leaflets on the compound 

 leaf were petioled, but, perhaps owing to this fact, they are by no means so 

 commonly found attached to the stems as the upper ones. The leaves are 

 so much like those of Saplndus that perhaps they might with jn'opriety be 

 placed in that genus. They seem to be at least ancestral forms of Sapindus. 

 The leaves of some species seem to be very variable within certain limits. 



Sapindopsis coedata, sp. nov. 



Plate CXLVII, Fig. 1. 



Leaf small, oblong with a subcordate base of thick consistency; mid- 

 nerve and petiole strong, nervation mostly concealed by the thickness of 

 the leaves ; primary nerves as seen very slender, going off at an angle of 

 about 45°, and half-way to the margin bending suddenly forward to connect 

 with the next primaries, sending off at the point of sudden bending a branch 

 which connects with the next lower primary. 



