1902] NOTES ON SASSAFRAS 443 



berry in his S. cretaceum; his figure however differs from Lesquer- 



eux's in that the primaries are as in the modern Sassafras and 



not sub-basal, as in the leaf figured by Lesquereux. It is well 



to consider these leaves as belonging to the Cissoid group. 



The veins, both primary and secondary, are straighter than in 



Sassafras, and more ascending, and are usually craspedodrome 



and not camptodrome as in Sassafras. All are found in Dakota 

 strata. 



Sassafras progenitor Newberry. — Newberry is very posi- 

 tive that this leaf is a true Sassafras, with which view 

 we entirely agree. The small leaf is the exact counter- 

 part of the modern Sassafras leaf in outline and vena- 

 tion, with the exception that the primaries are basal. While 

 no marginal veins are visible at the sinuses, the first second- 

 aries leave the midrib and curve upward, running directly 

 to the sinuses as in the existing Sassafras leaves. Rol- 

 lick's specimen from Long island, while fragmentary, has a 

 short branch running to the sinus in the half of the leaf blade 

 which is preserved. Newberry's other figures each lack the 

 basal portion of the blade and one of the lateral lobes ; the lobes 

 are more obtusfe than in his smaller specimen. While the sinus 

 appears to lack a marginal vein, the disposition of the second- 

 aries and tertiaries in this region is Sassafras-like. The species 

 is thus far confined to the Potomac formation, extending from 

 the Amboy clays to the Island series, and is remarkable in that 

 a Lower Cretaceous form should resemble so closely the existing 

 species. 



Sassafras dissectum Lesq. — These very large, palmately 

 five-lobed, coriaceous leaves from the Dakota formation of 

 Kansas were hardly borne upon a Sassafras tree. They resem- 

 ble somewhat 5. mirabile and Platanus pnmaeva, and Lesquereux 

 considers them^^ a possible link between these two genera. 

 Later he compares them to Aspidiophylhim trilobatum, from 

 which they differ in their entire lateral lobes; in the smooth 

 and not rugose areolation ; and in having a narrow decurrent, 

 instead of an expanded base. Aside from the character of the 



38 



Fl. Dak, Group, p. loi. 



