1855.] HOOKER RHYTIDOSPORUM OVULUM. 503 



Prestwich, IMr. Morris, and Mr. Jones to living genera, with few 

 exceptions. 



Before entering upon the suhject of its affinities, I shall describe 

 the genus, premising, however, that I have assumed it to be Crypto- 

 gamous, and have employed a corresponding terminology. 



Genus Carpolithes. Spor'angium coriaceum, oblongum, basi hilo 

 notatum, apice mamilla conica poro pertusa instructum, uniloculare, 

 saccum sporuliferum continens. Saccus membranaceus, hyalinus, 

 reticulatus, loculo conformis, basi lato sessilis, fundo sporangii tan- 

 tum adnatus, cseterum liber, apice conicus, poro instructus. Sporcc 

 majuscuise, oblate-sphericse vel discoideae, centro depressse, 3-mul- 

 tilobse, e sporulis cuneiformibus radiatim dispositis conflatsc. typo- 

 rulcE subtilissime striolatae ; striis radiantibus. 



1. Carpolithes ovulum, Brongn. Descript. Geologique des 

 Environs de Paris, t. 11. f. 6. 



Hab. Terra argillacea fluviatili Eocena ad "Counter Hill," prope 

 villam *' Lewisham," Comitate "Kent;" invenit beat. Rev''"' Dom. 

 H. de la Cotidamine. 



Sporangium atrum, carbonaceum, longit. ^V unc, diametro majore 

 \ unc, compressum, verosimiliter distortum : parietes coriacei, e 

 stratis plurimis cellularum formati, superficie creberrime areolati, 

 opaci ; margine altero acuto, altero subincrassato et vasis lignosis 

 scalariformibusque percurso ; mamilla conica terminal! basi disco 

 elevato circumdata. Saccus internus hyalinus, humectatus hygro- 

 metricus, e membranis duabus tenuissimis arete accretis formatus ; 

 areolis cellularum transverse oblongis, apicem conicum versus mino- 

 ribus et valde conspicuis. Sjwrcs majores ^^ unc. diametro, minores 

 r^ unc, omnes centro translucidse, pallide flavae. 



For the reference of this fossil to Brongniart's Carpolithes ovulum 

 I am indebted to Mr. Morris's extensive and accurate acquaintance 

 with the literature of Paiseobotany, as well as with the plants them- 

 selves, he having recognized both this and the Folliculites, which I 

 shall next describe, on my showing him my drawings and analyses. 



The C. ovidimi was first noticed in Cuvier and Brongniart's ' De- 

 scription Geologique des Environs de Paris,' as having been found 

 associated with tertiary freshwater fossils. M. Brongniart hesitated 

 whether to consider it as a seed or a monospermous pericarp, and 

 very doubtfully suggests a possible affinity with Nymphceacece. This 

 alliance is not, however, alluded to under NymphcJcacecB in his later 

 ' Tableau des Genres de Vegetaux fossiles,' and is, I presume, 

 abandoned . 



It is remarkable that the additional knowledge we now possess of 

 this fossil should throw no more direct light upon its affinities. 

 Even if we discard the idea of its being a sporangium and of crypto- 

 gamic origin, the terminal mamilla is very peculiar, and the definite 

 aperture at the apex of the internal sac is hardly analogous either to 

 the micropyle in the testa of a seed, or to any opening in the mem- 

 brane enclosing the albumen. The arrangement of the cells of which 



