174 Pi'"/- Don's Descriptions of two new Genera of the 



riiua, parva, adpressè 4-rariàin iiabricata, ovata, obtusa, coriacea, luîvis- 

 siina, nitida, viridia, J — 2 lineas longa, liinc obsolete carinata, inde con- 

 cava, basi lata adhœrentia, margine perangusto scarioso. Amenfii mu.s- 

 culii in ranmloinm apice solitaria, sessilia, laxè capitata, basi squamis 

 (foliis mutatis) pluribus, obiongis, obtusissimis, inde concavis, margine 

 scai'ioso-membranaceis involucrata. Sqtiamce antheriferce pauciores et 

 majores, ellipticœ, obtusœ, inde concavœ, rnfescentes, nmrgine membra- 

 naceie : nngiie angiistè lineari, compresso. Antherurnm tliecœ 2, ovatee, 

 obtusa^, ad peripheeriam inferani rima bivalvi déhiscentes. Amenta fœ- 

 m'inea subrotundo-ovata, omnino ut in |)rœcedente, sed squamse pauciores 

 et paullo latiores. Strohili duplo minores, subrotundi : sqnamis cuneato- 

 lanccolatis, lignosis, stipitatis, regione placentiferâ maxime protuberanti, 

 quasi subpeltatâ, trigonâ, superficie iuœquali : A///>/7e compresso-tetra- 

 gono : apiee triangulari-ovato, acuto, incumbenti. 



The habit of this singular genus recalls to mind the Lepidodendra, those 

 forms which at present exist only in a fossil state , the axis is studded with 

 the persistei\t adherent bases of the leaves, resembling the lozenge-shaped 

 marks on the stem of the fossil genus above-mentioned, and the ramification 

 frequently presents a dichotomous appearance, which arises from the nonde- 

 velopment of one of the lateral branches, the normal arrangement being a 

 primary axis with two opposite lateral branches. The bases of the leaves of 

 Li/copodiacece being so completely continuous with the axis would not pre- 

 sent such marks as those mentioned, and I am therefore inclined to consider 

 Lepidodendron as allied rather to Cuniferw than to that family, and the in- 

 teresting genus above described appears to present us with an evident link of 

 connexion. I have not had an opportunity of examining tiie internal struc- 

 ture of Lepidudendnm, but it is a subject well deserving investigation to 

 ascertain whether the vessels composing its woody tissue present that uni- 

 formity and dotting which prevail throughout Conifercv. 



The feuiale spike in Atlirotuxis, uidike that of most of the other genera of Cii- 

 pressinecv, forms a regular strobilus as in Pinii.s, and the scales are very thick, 

 u'oody and persistent, as in the normal group of that genus. I have assumed 

 that they are composed of a bracte and pericarpium, which are here completely 



