48 



BRITISH EOCENE FLORA. 



L.fronde fertili snperne simpliciter , inferne hi-vel ternatO'pinnata,pinnis simplicibus vel 

 bi-tripartitis, laciniis integris, dentatis, fructiferis spicas lineari-ohlongas compresms 

 obtusiusculas formans ; fronde sterili incequaliter bi-tri-quadri-partita vel simplice, 

 undulata ; lobis inaquilongis, sub angulis acutis, variis divergentibus, e basi plus minusve 

 dilatata, elongato-lanceolatis, apice obtusis ; nervatione Cgclopteridis composite, nervis 

 primariis itmquilongis subflexuosis ; nervis secundariis densis, sub angulis acutissimis 

 orienlibus, prominentibus tridichotomis. 



Middle Bagshot, Bournemouth. 



The pinnae in this species, as in most Lggodia, are variable, and may be entire 

 when little developed or cleft palmately into tv^^o, three, or four divisions. All these 

 forms are represented on PI. VII, and might have occurred on the same plant. The 

 lobes are usually unequal, and diverge from each other at angles of from 30° to 60°. 

 They are narrovv^, lanceolate, sometimes very elongate, generally widened at the base, 

 where they are confluent, undulate, more or less acuminate, but sometimes obtuse at the 

 terminations. The venation, enlarged in fig. 6, is that of Cgclopteris composita. The 

 primary veins are divergent and curved from the base, sinuous, attenuated upwards, 

 excurrent or lost in the lamina (fig. 7). The secondary veins are close together, and given 

 off at acute angles of from 10° to 30°, thrice forked, and so sharply defined throughout 

 their whole course that their ramifications are discernible without the aid of a lens. The 

 lobes of the fertile pinnge are petiolated (PI. X, fig. 11) ; in the upper part solitary or 

 undivided, but in the lower part two or three occur together or are twice or thrice 

 divided. The pinnules are linear, elongated, rather obtuse, and finely toothed on the 

 margin, and the rachides were not winged. A small fragment was figured by Heer 

 from the Eocene beds of Skopau. His enlargement is in form and venation identical 

 with ours, and they cannot be specifically separated, as was indeed first pointed out by 

 Heer^ himself. A comparison, by Lesquereux, of actual specimens from Bournemouth 

 has shown, as appeared evident from the plates and description, that L. neuropteroides 

 and the English species were one. Lesquereux says^ that "it is positively identical." 

 Dr. Crie also has found it in the Eocene Gres de la Sarthe." Other allied species, 

 L. parvifolium and L. exquisitum, have been found at Aix in Provence, and Count 

 Saporta informs us that the fertile fronds in these are identical with the British form. 

 Since pinnae are comparatively rare in all these widely separated localities we may infer 

 that Lygodiwn had a still greater geographical range in Eocene times. 



The two fossils described by Watelet as Lygodium, from the Paris Basin, belong to 

 one species, and this bears little resemblance to any belonging to that genus. 



L. Kaulfussi appears nearly allied to the form described as Miocene. Heer, in his 

 * Tertiarflora der Schweiz,' vol. i, pp. 41 — 43, distinguishes five species ; but, from the 

 figures, the propriety of giving them specific rank seems doubtful, especially in a Fern 



^ In letter. ^ In letter. 



