330 PALEOZOIC TIME. 



2. Sigillarids, Stigmarice. — Fig. 622, Sigillaria oculata Brngt., from Trevorton, Pa.; 

 623, <S. obovata Lsqx., from Pennsylvania and Kentucky; 624, St igniariaflcoides Brngt , 

 portion of a stem, showing the scars and the bases of the root-like appendages. 



According to Carruthers, who sustains, by his observations, the cryptogamic character 

 of Sigillarids and Stigmarice, the fruit of the Sigillaria is a cone with a single patch of 

 small sporangia on the enlarged base of the scale. Schimper gives it the name Sigilla- 

 riostrobus, and figures a cone. 



3. Ferns. — Fig. 628, the scar of the Tree-fern, Caidopteris punctata Lsqx., from the 

 Gate vein, Pennsylvania ; Fig. 629, same of Megaphytum McLeayi Lsqx., from Il- 

 linois. Fig. 629 A, scar of Cyathea compta, a species growing in the islands of the 

 Pacific. With the growth of the tree, as new fronds are unfolded, the old ones drop 

 off, each of which leaves its scar. The manner in which the fronds of ferns unroll, as 

 they expand, is shown in the sketch on page 322. 



Fig. 630, portion of a frond of Odontopteris Scklotkeimii Brngt., from Pennsylvania 

 and Europe; the whole frond is tripinnately divided, and of very large size. This 

 genus is mostly of the Lower Coal-measures. All the species of Hymenophyllites, with 

 several of Alethopteris, Neuropteris, and Pecopteris, are found in the Lower Coal. 

 Fig- 631, Alethopteris lonchitica Brngt., exclusively of the Lower Coal; Sphenojjteris 

 tridactylites Brngt. is also from the Lower Coal; Fig. 632, Hymenophyllites Hildrethi 

 Lsqx., from the Kanawha Salines, and 632 a, the same, enlarged; Fig. 633, Sphenopteris 

 Gravenhorstii Brngt., common in Ohio and farther west, at the Gate Vein, Pennsylvania, 

 and occurring also in England and Silesia; 633 a, a portion of the same, enlarged. 



Figs. 634, 634 a, Neuropteris Loschii Brngt., and Fig. 635, Neuropteris hirsuta Lsqx. 

 from figures b)' Lesquereux, both very common in the Upper Coal-measures, in Ohio 

 and Kentucky, and the former particularly abundant in the Pomeroy bed ; the speci- 

 mens of the latter are sparsely covered with hairs, which are well shown in specimens 

 from Morris, Illinois. Fig. 636, Pecopteris arborescens Brngt., common in Pennsylvania, 

 and Ohio. P. cyathea '.Brngt. and P. unita Brngt. are also common in the United States, 

 occurring in the Rhode Island coal-fields as well as elsewhere. Alethopteris Serlii Giipp.. 

 is another common species of the Upper Coal-measures, which is found also in Europe. 

 Fig. 637, Cyclopteris elegans Lsqx., found in the Shamokin Coal-bed, Pennsylvania. 



In Arctic America, on Melville Island, impressions of a Sphenopteris have been ob- 

 served in connection with the coal. 



4. Calaniitids. — Fig. 641 represents C. cannceformis Schloth , one of the Lower Coal- 

 measure species; 641 a, surface markings, at a joint; C. Cistii Brngt. and C. nodosus 

 Schloth. are other American Lower-coal species, as well as foreign; C. pachyderma 

 Brngt. is found only in the Millstone grit (Lesquereux). 



5. Asterophyllitids. — Fig. 639, Asterophyllites sublevis Lsqx.; Fig. 638, A. oralis Lsqx.',, 

 with the nutlets in the axils of the leaves; Fig. 640, Sphenophyllum Scklotheimii Brngt., 

 from Pennsylvania, Salem and Gate veins, and Pomeroy beds, Ohio. 



6. Gymnosperms. — Cordaites borassifolia Ung. is one of the common species of the 

 Coal-measures. Fig. 642 A, Cardiocaipus elongatus Newb., from Ohio; 642 B, C. bisec- 

 tus Dn., from Nova Scotia; 642 C, C. swmarmformis Newb., from Ohio; 644 a, b, c. 

 Trigonocarpus tricuspidattis Newb., from Ohio, representing the rind, the nut, and the; 

 kernel; 645, nut of another Ohio species, figured by Newberry, but not described; 646, 

 T. ornatus Newb., from Ohio; 646 a, view of extremity, showing the radiating ribs;. 

 646 A, Cardiocaipus bicuspidatus Newb., from Ohio. 



Fig. 643 represents the seed of the Welwitschia, now living in southern Africa. The 

 Welwitschia is an embryonic form of Conifer; it having (1) only two leaves, the coty- 

 ledonous, these being persistent, and increasing in width and length with the age of the 

 plant, and (2) growing to a height of only one or two feet, but spreading sometimes to 

 a diameter of four feet, without bark; and (3) bearing a group of large and beautifully 

 regular cones. It would seem to be, as Bentham has suggested, a type of Conifer 

 handed down from early geological time. But no such trunks have been found in the 

 Carboniferous or later beds. Although probably unlike Cordaites in its embryonic 

 features, it shows what leaves and fruit are consistent with the type of Conifers. 



Whittleseya elegans Newb., striated leaves over an inch wide and twice as long, is. 

 probably Coniferous, and related to Cordaites. 



