NATURAL SCIENCES OF PHILADELPHIA. 237 



ASTEROPHYLLITES. 



A. r ef 1 e xa nobis. 



Syn. Annularia reflexa Sternb. Vers. i. p. 31, t. 19, fig. 5. Asterophyllites 

 Brardii, Brongt. Prod. 



If this is a distinct species (which is doubtful) it must retain the specific 

 name of the first author. 



Sigillaria Brongt. 



Stem not articulate, corticate, costate, smooth or striate; ribs of various 

 widths, having furrows interposed between them ; cicatrices discoid, disposed 

 spirally upon the ribs, their longitudinal diameter exceeding the transverse ; 

 vascular scars varying in number, mostly linear. 



The great fossil botanist, Brongniart, united the three genera of Sternberg, 

 (Rhytidolepis, Favularia and Syringodendron,) with the title of Sigillaria. 

 More modern authors have, however, reseparated them, retaining Brongniart's 

 name for the first division of Sternb. 



Among recent writers, Messrs. Lindley and Hutton, have acknowledged the 

 genus Favularia, but Unger, Lesquereux and others do not. We have not 

 seen sufficient specimens of this genus to justify us in offering an opinion. 



Rhytidolepis, has, we believe, the right of priority over Sigillaria, but as the 

 latter is now universally employed, it would cause too much confusion to re- 

 vert to the original title. 



M. Bronguiart says, (see top of page 393, Veg. Foss.) " this genus is charac- 

 terized by the longitudinal diameter of scars at least equalling the transverse, 

 and that ordinarily it is much greater." A very few of the species which we 

 would recognise as true Sigillaria, depart slightly from this rule, but it is im- 

 possible to characterize a genus in fossil botany, some of whose forms will not 

 approach those of another division, for the simple reason, that any classifica- 

 tion, however ingenious, must necessarily be purely artificial. 



According to the oldest classification, all fossil plants were referred to the 

 two genera, Filicites and Phytolithus. The present system has arisen by 

 splitting off", as it were, section after section from these. 



The classification of vegetable reliquse may thus continue to advance, and it 

 is with the hope it may prove a step in the right direction, that we propose 

 a partial revision of the genus Sigillaria. 



S. perplexa, n. sp. Stem costate, costa varying in their width; bark 

 thin ; cicatrices quadrangular, conjoined by their raised confluent borders ; 

 vascular scars obsolete. 



We place this very remarkable fossil in this group until better specimens 

 can be obtained for further stud)'. Though the vascular scars are not pre- 

 served, yet we cannot say they have never existed. When the bark is stript 

 from the stem, a raised border is seen to underlie the margin of external scar. 

 Locality and position unknown. Cabinet of the Academy. 



S. solan us, n. sp. Stem costate ; ribs strongly convex, striate, and with 

 a striate groove in the middle; cicatrices placed in this groove, small, distant 

 subdiscoidal, often elongated with iheir base rounded and apex somewhat 

 truncate ; vascular scars three, those on the sides linear, arcuate. 



In our specimen the distance between the scars is about five times their 

 length. The depression or channel is slightly widened at their position, and 

 between them a band, equalling them in width, is finely chased by very numer- 

 ous minute striae. Locality, Shaever's Drift, East Norwegia. Position unknown. 

 Collection of the Academy. 



Asolancs nobis. 



Stem not costate, striate ; striae straight or curved, regularly or irregularly 

 disposed ; cicatrices discoid, single, their transverse exceeding the longitudinal 

 diameter ; vascular scars varying in number, mostly linear. 



1860.J 



