The sporangia of _Hyphochytrium infestans_[426], as figured by Fischer in Rabenhorst’s work bear a close resemblance to those of the fossil. It would seem very probable that Renault’s species may be reasonably referred to the Chytridineae, as he proposes. [Illustration: FIG. 43. 1. _Oochytrium Lepidodendri_, Ren. (After Renault.) 2. _Polyporus vaporarius_ Fr. var. _succinea_. (After Conwentz.) 3. _Cladosporites bipartitus_ Fel. (After Felix.) 4. _Haplographites cateniger_ Fel. (After Felix.)] _Peronosporites antiquarius_ W. Smith. Fig. 41, E. In an address to the Geologists’ Association delivered by Mr Carruthers in 1876 a brief reference, accompanied by a small-scale drawing, is made to the discovery of a fungus in the scalariform tracheids of a _Lepidodendron_ from the English Coal-Measures[427]. In the following year Worthington Smith published a fuller account of the fungus, and proposed for it the above name[428], which he chose on the ground of a close similarity between the mycelium and reproductive organs of the fossil form and recent members of the Peronosporeae. In Smith’s description the mycelium is described as bearing spherical swellings containing zoospores. These spherical organs are fairly abundant and not infrequently met with in sections of petrified plant-tissues from the English Coal-Measures; they may be oogonia or sporangia, or in some cases mere vesicular expansions of a purely vegetative hypha. No confirmation has been given to the supposed spores referred to by Smith. Prof. Williamson and others have carefully examined the specimens, but they have failed to detect any trace of reproductive cells enclosed in the spherical sacs[429]. The mycelium does not appear to show any satisfactory evidence of its being septate as figured by Smith. The example shown in fig. 41 E has been drawn from one of the Williamson specimens: it illustrates the form and manner of occurrence of the characteristic swellings. It is probable that some at least of the vesicles are either sporangia or oogonia, but we cannot speak with absolute confidence as to their precise nature. The general habit and structure of the fungus favour its inclusion in the class of _Phycomycetes_. The occurrence of several of the vesicles close together on short hyphal branches, as shown in Williamson’s figures, suggests the spherical swellings on vegetative hyphae, but it is impossible to speak with absolute confidence. There is a close resemblance between this English form and one recently described by Renault as _Palaeomyces gracilis_ Ren.[430]; the two fossils should probably be placed in the same genus. The examples referred to below and originally recorded by Cash and Hick no doubt belong to the same type as Smith’s _Peronosporites_.