CENOZOIC TIME — TERTIARY. 



915 



1544. 



Since Rodents have been described from the same beds, and a skeleton 

 of one has been found at the base of one of the spirals, there has seemed 

 to be strong reason for regarding them as the core of a fossil burrow ; and 

 this has appeared to be confirmed by the fact that the skeleton belonged to 

 a Rodent that was of the right 

 size to have made the spiral 

 cavity. But according to the 

 latest investigations of E. H. 

 Barbour (published in Novem- 

 ber, 1894), the spiral stems or 

 fillings have a cellular struct- 

 ure, as if of vegetable origin. 

 The oblong cells average one 

 thirty-second of an inch in 

 diameter, but vary from one 

 sixty-fourth to one eighth, and 

 even to one fourth. The ex- 

 terior is made of these tubules 

 variously intertwined. The 

 whole of a spiral and its long 

 transverse continuation at base 



have the cellular structure. " Each and every well-cut section shows paren- 

 chymatous tissue, no matter from what specimen, or from what portion of 

 an individual specimen, the section is made ; there has not been an excep- 

 tion to this." The final conclusion therefore is that the fossil having the 

 spiral form, together with its basal portion, was probably some kind of 

 plant, and that it grew around the inclosed skeleton. 



Two views of a specimen of Daemonelix. 

 E. H. Barbour. 



Characteristic Invertebrate Species. 



EOCENE. 



1. Midway. — Enclimatoceras Ulrichi White, Ostrea Pulaskensis Harris, Ostrea 

 prce-compressirostra Har., Pecten Alahamiensis Aldrich, Yoldia eborea Conrad, Cucullcea 

 raacrodonta Whitfield, Cadulus turgidus Meyer, Caricella LeanaDaM, Valuta Showalteri 

 Aldrich, Volutilithes rugatus ConvduA, Volutilithes limopsis Con. , Leucozonia biplicata Aid- 

 rich, Neptunea constricta Aldrich, N. Matthewsensis Aldrich, Pseudoliva unicarinata 

 Aldrich, Murex Alahamiensis Aldrich, Turritella Alahamiensis Whitfield. 



2. LiGNiTic. — Maryland and Virginia : Ostrea compressirostra Say, Cucullcea gi- 

 gantea Conrad, Crassatella aloeformis Conrad, Dosiniopsis lenticularis, Cytherea ovata 

 Rogers, Panopcea elongnta Conrad, Pholadomya Marylandica Conrad, Turritella prceciticta 

 Conrad. Alabama : Ostrea compressirostra, 0. thirsas Gabb, Cuculloea gigantea Con., var., 

 Cra.ssatella tumidula Whitfield, Dosiniopsis lenticularis, Pholas alatoidea Aldrich, Voluta 

 Newcomhiana Whitfield, Pseudoliva tuberculifera Conrad. Upper beds, Alabama : Fusus 

 interstriatus Heilprin, Pleurotoma raoniliata Heilprin, Lcevibuccinu7n lineatum Heilp., 

 Pseudoliva scalina Heilp., Corhula Aldrichi Meyer, Cardium Hatchetigheense Aldrich. 



.3. Lower Claiborne. — Ostrea Johnsoni Aldrich, Anomia ephippoides Gabh, Toldia 

 Claibornensis Conrad, Trigonarca pulchra Gabb, Crassatella antestriata Gabb, C. 



