219 



a very distinct smaller-leaved species in the Magothy formation 

 at Grove Point, Maryland. This may be characterized as follows : 



Bauhinia marylandica sp. no v. 



Leaves small, about 3 cm. in greatest length by 2.5 cm. in 

 greatest breadth, elliptical in general outline, bilobate ; the apical 

 sinus narrow and pointed, reaching one-half to two-thirds of the 

 distance to the base ; lobes narrow, ascending, somewhat falcate 

 in outline, obtusely pointed ; midrib straight, giving off one, two, 

 or three sharply ascending pairs of opposite, camptodrome sec- 

 ondaries, which give off a series of broadly rounded inequilateral 

 tertiary arches which are directed upward and outward ; the upper 

 pair of secondaries the most prominent ; from the juncture of the 

 midrib and sinus a pair of much reduced secondaries is given off 

 and these join the secondary next below^ in one or two broad 

 arches. 



The form and venation of these leaves is exactly like several 

 of the existing forms and is so well marked that there can be no 

 doubt of the existence of a species of Bauhinia growing along 



the coast of Maryland during the deposition of the Magothy form- 

 ation, a species whose descendants along with those of its Creta- 

 ceous congeners migrated finally to their present tropical habitat, 

 perhaps gradually with the oscillation of climatic conditions, and 

 perhaps not until the Pleistocene glaciation to the northward forced 

 them to make a comparatively sudden retreat to the southward. 



Johns Hopkins University, 

 Baltimore, Maryland. 



