IOWA ACADEMY OF SCIENCES, 61 



CARDIOCARPUS IN IOWA. 



BY ARTHUR J. JONES. 



While engaged in geological work in Guthrie county a number of peculiar 

 seed-like structures were collected from a seam of bituminous coal. They occurred 

 in the newly opened mine of Mr. Scott, three miles northwest of Fanslers. 



These seeds are not more than half an inch long and are quite thin. They are 

 acuminate and vary from oval to broadly heart-shaped. At the base is a scar evi- 

 dently indicating the juncture of the stem. No connection, however, was seen 

 between the seed and the stalk of any plant in the coal. They are covered with a 

 thin coating of pyrite and they all occurred in an eighteen-inch vein of coal. 



Similar seeds are described by Lesquereux and Newberry as belonging to the 

 genus Cardiocarpus and found in the coal measures of Pennsylvania, Ohio and 

 neighboring states. The structures observed are evidently merely nuclei, although 

 scarcely a trace of an encircling rim can be seen on any of them. The specimens 

 collected are similar to the nuclei of Cardiocarpus bicuspidatus and C. zonulatus. 



It is now generally conceded that the seeds called by the generic name Cardio- 

 carpus are merely the mature fruit of certain species of Cordaites. The Cordaitese 

 form a distinct order of gymnospermous plants very closely allied to the Cycads 

 on the one hand and to the conifers on the other. They, however, bear a strong 

 resemblance to the Lycopods and for some time were classed under this head. The 

 living plant which most nearly resembles Cordaites is Cycas revoluta. Newberry 

 says that the fruit Cardiocarpus was probably somewhat drupaceous when living, 

 the nucleus being entirely concealed, but compressed by the great weight of the 

 overlying strata it has become flattened ; the fleshy pericarp is now the thin mem- 

 braneous rim, and the nucleus appears at the center, not so much crushed on 

 account of its more solid structure, but somewhat flattened. 



This fruit and other remains of Cordaites have been found in Ohio, Pennsyl- 

 vania, Tennessee, Indiana, and various other states, but they have not been reported 

 from Iowa. 



