Maryland Geological Survey 267 



The flora received its first systematic treatment by Goeppert ' in 1841 . 

 Debey, who greatly interested himself in collecting the vegetable remains 

 from these beds, was a practising physician in Aachen for many years 

 and amassed large collections which unfortunately became scattered after 

 his death. He commenced publishing 2 in 1 848, and with the collaboration 

 of Ettingshausen 3 succeeded in 1856 and 1859 in placing the Thattophyta 

 and Pteridophyta in a condition which made them available to students 

 of paleobotany. Then followed a period of eighteen years during which 

 he published nothing. In 1877 there appeared ' a short paper on conifer- 

 ous remains and in 1880 another short paper 5 was devoted to the oak- 

 like dicotyledons (Dryophyllum). Meanwhile in 1849 Pomel 6 had 



1 Goeppert, Fossile Pflanzenreste des Eisensandes von Aachen, als zweiter 

 Beitrag zur flora der Tertiargebilde. Nova Acta Acad. Leop. -Carol., Bd. xix, 

 Pt. 2, 1841, pp. 139-160, pi. liv. 



2 Debey, Uebersicht der urweltlichen Pflanzen des Kreidegebirges iiberhaupt, 

 und der Aachener Kreideschichten insbesondere. Verhandl. naturhist. Ver. 

 preuss. Rheinl., Westfalens, Bd. v, Jahrg. 1848, pp. 113-125. 



Debey, Ueber eine neue Gattung urweltlicher Coniferen aus dem Eisensand 

 der Aachener Kreide. Ibidem, pp. 126-142. 



Debey, Entwurf zu einer geognostisch-geogenetischen Darstellung der 

 Gegend von Aachen. Bericht 25. Versamml. deutsch. Naturf., 1849, pp. 269-328, 

 pi. iv (sections). 



Geinitz, Bemerkungen zu Debey's Entwurf etc., Neues Jahrb., 1850, pp. 

 289-301. 



Debey, Beitrag zur fossilen Flora der hollandischen Kreide (Vaels bei 

 Aachen, Kunraed, Maestricht). Verhandl. naturhist, Ver. preuss. Rheinl., 

 Westphalens, Bd. viii, Jahrg. 1851, pp. 568-569. 



3 Debey u. Ettingshausen, Uebersicht der gesammter Aachener and Mae- 

 strichter Kreideflora. Bericht 32. Versamml. deutsch. Naturfor., 1856. 



Debey u. Ettingshausen, Die Urweltlichen Thallophyten des Kreidege- 

 birges von Aachen und Maastricht. Denks. k. Akad. Wiss. Wien, math.-nat. 

 CI. Bd. xvi, 1859, pp. 131-214, pi. 1-3. 



Debey and Ettingshausen, Die Urweltlichen Acrobryen des Kreidegebirges 

 von Aachen und Maestricht. Ibidem, Bd. xvii, 1859, pp. 183-248, pi. i-vii. 



4 Debey, Eine Uebersicht der fossilen Coniferen der Aachener Kreide. 

 Verhandl. naturhist. Ver. preuss. Rheinl., Westfalens, Corr.-Blatt, Bd. xxxiv, 

 1877, p. 110. 



5 Debey, Sur les feuilles querciformes des sables d'Aix-la-Chapelle. Compte 

 rendu du Congres de botanique et d'horticulture, 1880, pt. ii, Bruxelles, 1881, 

 pp. 1-16, pi. 1. 



6 Pomel, Materiaux pour servir a. la flore fossile des terrains jurassiques 

 de la France. Bericht 25. Versamml. deutsch. Naturfor., 1849. 



