136 Mr. R. Kidston on the Relationship 



case, the specimens denominated Halonia formed the ter- 

 minal or young branches of Ulodeyidron'''^. 



1880. Zeiller. Vegetaux fossiles du terrain houiller de la 

 France (extracted from vol. iv. De I'explication de la carte 

 gdologique de la France, p. 114). — This botanist writes: 

 " At present several authors unite the Ulodendra to the 

 Lepidodendra ; I cannot see my way to adopt this view, at 

 least in the case of U. maj'us and U. minus. ^^ .... " I do 

 not pretend, however, that all the Lycopodiacese with branches 

 provided with large circular depressions ought to be separated 

 from the genus Lepidodendro7i, and that we miglit not meet 

 with trunks of this genus presenting this peculiarity ; practi- 

 cally it exists in the genus Bothrodtndroh.'''' '\ ..." I believe 

 in the justice of regarding the genus Ulodendron as a special 

 genus, distinguished from Lepidodendron by the mode of 

 attachment of its leaves." 



1880. Lesquereux. Coal Flora of Pennsylvania, p. 397. — 

 This author practicf.lly adopts the views held by Schimper. 

 As to appendicular organs Lesquereux thinks that in some 

 cases they have been cones, in others " bud-like excrescences." 

 This latter opinion is chiefly based on his Ulodendron Mans- 

 jieldi (pi. Ixvii. fig. 2), whicli, I think, may perhaps not 

 belong to Lindley and Hutton's genus Ulodendron. 



1882. Renault. Cours de botanique fossile, deuxi^me 

 annde, p. 49. — Ulodendron is by this author treated as a 

 true genus. He says : " Often a portion of the surface of 

 these disks [Ulodendroid scars] is covered by the foliar cica- 

 trices, a continuation of those of the trunk, but becoming a 

 little smaller; it is necessary, then, that these disks should be 

 understood as the flattened remains of a conical fleshy mamelon, 

 of which the surface in continuation of that of the stem would 

 have been covered with similar but smaller leaves. At the 

 centre of the mamelon had been the axis of a caducous cone, 

 of which the traces are indicated by the central umbilicus ; 

 the considerable number of vascular buirdles which converge 

 towards this part indicates a vegetative activity not in ac- 

 cordance with an abortive branch, but only with an axis, 

 destined to bear organs of reproduction. 



" We have separated from this genus, which is characterized 

 by the form of the foliar cicatrices and by its biserial disks, two 



* It is now conclusively known that '■^Halonia " is the fruiting branch 

 of Lepidophloios ; hence it cannot possibly be " terminal or young branches 

 of Ulodendroti^ 



t The plants placed in Bothrodendron by Zeiller are not similar to 

 those included in Bothrodendron by Lindley and Hutton ; but this point 

 will be spoken of more fully presently. 



