﻿3^4 SMITHSONIAN MISCELLANEOUS COLLECTIONS [VOL. 47 



recently been supported by Miss Benson, 1 who discussed the con- 

 nection of these organs with Lyginopteris not long" before the 

 indisputable correlation, by Oliver and Scott, 2 of seeds (Lagenos- 

 toma of Williamson) with the same plant, on the basis of the strongly 

 characteristic anatomical features. The fruit described as L. Lomaxi 

 is orthotropous, small, only about one-half a centimeter in length, 

 and is borne in pedicellate cupules. The seed, with chalaza, testa, 

 nucellar epidermis, pollenic chamber, etc., is essentially gymno- 

 spermic in structure, though exhibiting certain very unique and 

 striking features. 



While related to the ferns by its leaves, young roots, and micro- 

 sporangia, the predominant analogies of Lyginopteris are gymno- 

 spermous. The mesarch arrangement of the elements in the primary 

 wood strands is to be compared with the structure in the petioles and 

 peduncles of certain living Cycads to which it is almost peculiar. 

 The change in the leaf strand from the collateral to the concentric 

 form while passing to the petiole also finds an analogy in Osmunda. 

 The very large pith and the loose spongy secondary wood suggest 

 the Cycads, and the seeds are comparable to those of Ginkgo. 



Megaloxylon. — The genus Megaloxylon of Seward' 5 includes 

 stems of considerable size which contain a large primary cylinder of 

 short tracheides mingled with parenchymatous tracts. The thick 

 secondary wood is like that of Lyginopteris. The genus is thus 

 closely related by its primary stele and its centrifugal xylem to both 

 Heterangiiim and Lyginopteris; but it differs by the exarch struc- 

 ture of the bundle in both the primary xylem and the leaf trace. 



Calamopitys. — Closely related to Lyginopteris are the slender 

 monostelic stems, from the Lower Carboniferous of Thuringia, de- 

 scribed by Unger as Calamopitys. This stem 4 has pith, primary and 

 secondary wood like that of Lyginopteris. The centripetal trache- 

 ides are pitted on all sides ; the centrifugal on the radial walls only. 

 Calamopitys differs from the genus last mentioned by the change in 

 the leaf strands to a concentric structure on entering the cortex, and 

 by the separation of the strand into several bundles arranged in a 

 ring in the petiole. The structure of the petiole, which accordingly 

 is fern-like, appears to be identical with that of Kalymma grandis 

 Ung., which has also been reported from the Middle Devonian Black 



1 Ann. /'('/., vol. xvi, 1902, p. 575. 



- I'roc. Roy. Soc, vol. lxxi, no. 474, May 26, 1903, p. 477; Philos. Trans., 



VOl. 197, B, 1904, p. 193. 



3 Proc. Cambr. Phil. Sac, vol. x, 1899, p. 158. 



4 See Solms-Laubach, Abh. k. Preuss. geol. Landesanst., Heft. 23, 1896, pp. 

 63 and 43; also Dawson and Penhallow, Can. Rec. Sri., vol. IV, 1891, p. I. 



