444 BOTANICAL GAZETTE [December 



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base, they also resemble Lesquereux's figure^^ of Aspidiophyllwn 

 dentatitm^ agreeing exactly except that in the latter the border 

 is sometimes obtusely dentate. 



Sassafras dissectum symmetricum Hollick, — What was said 

 of S. dissectum applies equally well to this variety, at least in so 

 far as its characters are known. The fact that the primaries are 

 opposite is hardly a varietal character, as witness the varia- 

 bility in this respect among leaves of the existing Sassafras. 

 The only other differential character, therefore, is that the leaf- 

 blade is not decurrent on the petiole but ends at the insertion of 

 the primaries. As the general shape of the base is like that of 

 the species, and as the variety is founded on a single imperfect 

 specimen, it would perhaps be well to consider it as identical 

 with 5". dissectmn, at least until the discovery of more complete 

 material. The specimen in question is from the Dakota forma- 

 tion near Fort Harker, Kansas. 



Sassafras cretaceum Newberry. — Newberry includes under 

 this name the various forms described by Lesquereux as 5. 

 Mtidgei, S. subifitegri folium, S. iJite grifoliiim , S. obtuswn, S, creta- 

 ceum dentatum, S, cretaceum obttisum , 5. aciitilobum^ Cissites 

 harkeriamis, and C, salisbtiriaef alius. While this shows the 

 undoubted composite nature of 5. cretaceum, it also shows that the 

 extremes of leaf form above mentioned are so closely connected 

 with the more typical leaf by a series of intermediate forms that 

 the question of where one species shall end and another begin 

 is an extremely difficult one. We consider the leaf figured on 

 pL 6. fig, /, Later Ext. Fl., to be the typical form of this species. 

 It bears considerable resemblance to some modern Sassafras 

 leaves. A slight widening of the terminal lobe of some of these 

 in the region of its base would give a leaf strikingly like S. 

 cretaceum; or w^ere the sinuses of the latter slightly deeper we 

 would have the typical modern leaf. The basal portion of the 

 leaf is like Sassafras, and the indications point to a similar 

 venation in this region. The first pair of secondaries do not 

 branch to form margins of the sinuses ; the left one runs 

 directly to the sinus, however, and may possibly have con- 

 's Fl, Dak. Group,//, jg^fig, i. 



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