1 78 Pt'of. Don's Descriptions of two new Genera of the 



Since the preceding observations were in type, I have been favoured by my 

 friend Mr. Smith, of the Royal Botanic Gardens at Kew, with a specimen of 

 Cunninghamia sinensis, bearing several male catkins, and a full-grown cone. 

 A careful examination of this remarkable plant has satisfied me that its proper 

 place in a systematic arrangement is among the Cupressinece, next to Athrotaxis 

 and Cryptomeria, to both of whom it is related in a nearly equal degree. In the 

 form, structure, insertion, direction, and number of its ovula it agrees entirely 

 with the former genus, from which it is principally distinguished by its elon- 

 gated aggregate male spikes, and by the addition of a third polliniferous theca. 

 The placentary region is crowned with a thin, narrow, minutely toothed border, 

 clearly of the same nature with the remarkable toothed organ, which I have 

 described as the pericarpium in Cryptomeria, and which, singular as it is, can 

 no longer be regarded in any other light than as an excessive development of 

 the placentary region, and what I have described as a bracte is really the apex 

 of the pericarpial leaf. The enlarged placentary region, and the erect ovula, 

 are characters amply sufficient to separate Cryptomeria from Cunninghamia, 

 in which the polliniferous thecee are fewer, and altogether free. The striking 

 resemblance, both in form and structure, of the antheriferous scales to those of 

 the female spike, and also to the bractes and leaves, clearly show that they are 

 all modifications of one and the same organ. In all the three genera above- 

 mentioned the antheriferous thecee bear an evident relation to the number of 

 the ovula, the latter apparently originating in all cases from the upper, and 

 the former from the inferior surface of the modified leaf. The direction of the 

 ovula, which in all cases are atropous, is evidently a character of no more than 

 generic value in this family. 



March 6, ]839. 



EXPLANATION OF THE PLATES. 



Tab. XIII. 



Fig. 1. Cryptomeria japonica. 



a. Antheriferous scale, front view, showing the five thecae. b. Ditto, 

 back view ; both magnified, c. Scale of cone, with its bracte, back 



