Maryland Geological Survey 421 



Although fruiting specimens have not been found, the position of the 

 genus in the Cupressineae based as it is upon similarity in habit, form, 

 and stomatal characters, is not disputed at the present time although 

 formerly Heer argued for an affinity with Ephedra. 



Named originally for its resemblance to the living species of Frenela 

 of the Australian region, we find the latest treatment of the modern 

 Cupressinese, that by Eichler in Engler and Prantl's Naturlichen 

 Pfianzenfamilien (1889), makes Frenela a subgenus of CaUitris Vent., 

 the latter being divided into four subgenera as follows: 



Octoclinis F. v. Miill. (Frenela Bentham) with eight scales to the 

 cones and a single species inhabiting Australia. 



Hexaclinis {Frenela Mirbel) with six scales, 3 large and 3 small, 

 and nine species of Australia and New Caledonia. 



Pachylepis Brongn. (Widdringtonia Endl.) with thick woody cones 

 of four subequal scales and having three or four species of South Africa 

 and Madagascar. 



Eucallitris Brongn. (Tetraclints) with four scales to the cones and 

 a single species of Northern Africa. 



However admirable this arrangement may be when only the living 

 species are considered, it will not answer for the fossil forms and paleo- 

 botanists quite rightly maintain the various genera Frenelites, Wid- 

 dringtonia, Widdringtonites, CaUitris, etc., ranging in age from the 

 older Mesozoic through the Tertiary and abundantly fortified by fruiting 

 specimens. Fossil fruits of still other species and perhaps genera occur 

 in the late Tertiaries of Australia, the weight of the evidence showing 

 that this type was considerably more varied in the past, the existing forms 

 being isolated remnants of a once almost world-wide distribution. 



Within the Potomac Group Frenelopsis raniosissima ranges from the 

 bottom to the top while F. pa/rceramosa appears to be confined to the 

 later beds serving by its resemblance to F. Hoheneggeri to connect them 

 with the overlying Earitan formation. 



The genus is not recorded from the English Wealden although certain 

 poorly preserved remains which fail to show joints or leaves but seem 

 to be similar in habit are described by Seward as a new genus and 



