CARBONIFEROUS AGE. 331 



The Stei-nbergia, which are abundant in Ohio, and at Pictou, Nova Scotia, have been 

 shown by Dawson and Williamson to be casts of the pithy or open cellular interior of 

 either Conifers or Lepidodendrids. They are thick, cylindrical stems, much wrinkled 

 circularly, consisting of the same arenaceous material as the rock in which they occur 

 buried. Occasionally, they have a carbonaceous exterior, which is the woody part of 

 the former tree. In Nova Scotia specimens, as well as those of England, a coniferous 

 structure has sometimes been observed in the coaly exterior, and also a very open cel- 

 lular structure through the sandstone interior. One of the Coal-measure species, from 

 Pictou, is not distinguishable, in its microscopic structure, according to Dawson, from 

 the Pinites (Dadoxylon) Brandlingi of Witham. 



7. Cryptogams. — Seaweeds are rare in the Coal-measures. A Spirophyton, like S. 

 Cauda-galli (p. 254), has been reported by Lesquereux as occurring in sandstone, prob- 

 ably of this era, or of the Subcarboniferous, in Crawford County, Arkansas. Species 

 of the genus Caulerpites have been observed in Pennsylvania, Illinois, Indiana, Mis- 

 souri, in both the Lower and the Upper Coal-measures. Chondrites Colletti Lsqx. was 

 obtained near Lodi, Indiana, overlying a thin coal-bed at the base of the Coal-measures. 

 Lesquereux remarks that, although the ironstone concretions have preserved the most 

 delicate parts of Ferns and Insects, no trace of a Fungus or Lichen has been found in 

 them. 



Characteristic Species of some of the Subdivisions of the Carboniferous. 



Lesquereux enumerates the following, among the species characteristic of the groups 

 below mentioned : — 



(a.) Millstone Grit. — Lepidodendron, six species; Sigillaria, two; Catamites, two; 

 Stigmaria ; and the Ferns, Pecopteris velutina Lsqx., P. nervosa Brngt., Neuropteris 

 flexuosa Brngt., N. hirsuta Lsqx., Annularia sphenophylloides Ung., Odontoptosis crenu- 

 lata Brngt., Hymenophyllites furcatus Brngt., Sjjhenopteris latifolia Brngt., which occur 

 also higher, to at least Coal-bed No. 1 B. 



(b.) Mammoth Bed (No. IB). — A great number of fruits, including nearly all of the 

 Coal-measures, of the genera Trigonocarpus, Cardioctrpus, Rhabdocarpus, and Carpo- 

 lithes; numerous Lepidodendra (eighteen species); Alethopteris lonchitica and A. mar- 

 ginata Gopp., not known above, and species of Callipteris, with feAV of the finer forms 

 of the family, of the genus Pecopteris ; among which few there are the Pecopteris velu- 

 tina Lsqx., P. Sillimani Brngt., P. plumosa Brngt.; Sjjhenopteris family numerously 

 represented, — e g., S. latifolia Brngt., S. obtusiloba Brngt., S. glandulosa Lsqx., S. 

 polyphylla L. & H., S. Newberry i Lsqx., S. artemisiazfolia Brngt., and Hymenophyllites 

 Hildrethi Lsqx. and H. spinosvs Gipp., all peculiar to it; all the American species of 

 Odontopteris, except 0. crenulata Brngt., found also in the Millstone grit. Manj r Sigil- 

 lorice, as S. stella ta Lsqx., S. Serin Brngt., S. tesselata Brngt., S. Brochand Brngt., 

 S. alveolaris Brngt., and others, not found above. The most abundant species are the 

 omnipresent Neuropteris hirsuta and N. flexuosa. There are also species of Annularia, 

 Sphenophyllum, Asterophijllites, and Catamites; and everywhere Stigmaria ficoides. 



(c. ) Coal No. 4. — This bed is characterized by small Ferns. There are no Lepido- 

 dendra, but some Sigillaria} ; and numerous species of the Pecopteris family ; also species 

 of Asterophyllites, many of Neuropteris, and several of Sphenopteris. 



(d.) Coal No. 8, the Pittsburg Coal-bed. —There are Neuropteris hirsuta Lsqx., Cor- 

 daites borassifolia Ung., Neuropteris flexuosa Brngt., Pecopteris polymorphs Brngt., P. 

 arborescens Brngt., P. cyathea Brngt., Sphenophyllum emarginatum Brngt.; Catamites, 

 three species ; Sigillaria, one species; Lepidodendron, none. Neuropteris Moorii Lsqx. 

 begins here, and has some resemblance to an Oolytic species. 



2. Animals. 

 The animal life of the Carboniferous period included, besides 

 marine Invertebrates, terrestrial Mollusks, and a large variety of 

 terrestrial Articulates, as Insects, Spiders, Myriapods ; and, among 



