IV 



Page 

 Figures in the Text. 



Fig. I. Geological sketch-map of Tømten and the environs. Scale i : 25.000 8 



„ 2. Two profiles of Tomten and just south of the same locality 10 



„ 3. Obolella roimidata nov. sp. Reconstruction of interior of shells, 7/1 .... 13 

 „ 4. Sketches of specimens of Torellella laevigata Lxrs. var. Holnii nov. var. with 



cross-sections 3/r 21 



„ 5. a. Almost perfect specimen of Strenuella strenua Billings after Shimer. b. Py- 

 gidium of Strenuella streinta Billings after Walcott. c. P3'gidium of Strenuella 



sp. after Moberg 45 



„ 6. Thoracic segments of Strenuella priinaeva Brogger, Ellipsocephahts Nordenskjøldi 

 Lnrs., El. muticus Lnrs., El poly tomus Lnrs. and El. Hoffi Bar., showing the 



gradual reduction of the pleural spines in these forms 48 



„ 7. Cranidia of Agraulos ceticephalus (a) and Ellipsocephalus Hofß Bar. (b) shows 



the difference between the two types 52 



„ 8. Hohnta Kjerulß Lnrs. Reconstruction, double natural size, of a small specimen, 



and a length-profile showing spines 60 



„ 9. Holinia Kjerulfi Lnrs. Reconstruction, natural size, of an older specimen . . 60 

 „ 10. Building of the cranidium of Holtnia Kjerulfi Lnrs. Somewhat in outline, 11. 



a. From the side. b. From in front, c. From behind, d. From the underside . 61 



„II. Six stages in the ontogenetic development of Holniia Kjerulfi Lnrs 67 



„ 12. Kjerulfia lata nov. sp. Reconstruction, natural size. Below we see the posterior 



dorsal spines in profile 74 



„ 13. Under side of cranidium of Kjerulfia lata nov. gen. & sp. In outline, i/i , . 77 

 „ 14. Articulation apparatus of Kjerulfia lata. a. Two thoracic segments showing inden- 

 tation in the posterior side of the dorsal furrow (articulation cavity), and the 

 bulb-like process (articulation process) that falls into the same, 2/1. b. Cavity 



and process of articulation somewhat dislocated, 4/1 79 



„ 15. a — b. Cavity and process of articulation in Asaphics expansus, after Brø~ger. 



c— d. Apparatus of articulation in the recent Astacus, after Lang. ... 80 



Plates. 



Plate L Obolella rotundata nov. sp. (figs, i — 11). 



„ II. Scenella anliqua nov. sp. (figs. I— ic) Scenella depressa nov. sp. (figs. 2 — 2c), 



Helcionella cf. rugosa Hall (figs. 3 — 3b), Hclcianella ritgosa Hall var. acuticosta 



Walcott (figs. 4 ■-4a). 

 „ III. Torellella laevigata Lnks. var. Holmi nov. var. (figs. 1 — 5), Hvolitlius sp. No. 2 



(fig. 61, Hyolithus sp. No. i (fig. 7 1, Hyolithus sp. No. 3 (figs. 8 & 11), Volbor- 



ihella tenuis Schmidt (figs. 9 — 9a), Hyolithus corrugatus nov. sp. (figs. 10— loa), 



IVeyinouthia nobilis Ford (figs. 12 — 12b). 

 „ IV. Strenuella priinaeva Brøgger (figs. 1—4), Strenuella Linnarssoni nov. sp. 'figs. 



5 — 6), Ellipsocepalus Nordenskjøldi Lnrs (figs. 7—8). 

 „ V. Strenuella primaeva Brøgger (figs. 1—6), Strenuella Linnarssoni nov. sp. (figs. 



7 — 10), Ellipsocephalus Nordenskjøldi Lnrs. (figs. 11 — 13). 

 „ VI. Holmia Kjerulß Lnrs. (figs, i — 11), Holmia grandis nov. sp. (fig. 12). Cranidia. 

 „ VII. Holmia Kjerulfi Lnrs. (Figs. 1—6). Eyes and hypostome. 



„ VIII. Holmia Kjeridfi Lnrs. (figs, i — ii). Cranidia with thoracic segments and pygidia. 

 „ IX. Kjerulfia lata nov. gen. & sp. (figs. 1—5)- Cranidia. 

 „ X. Kjerulfia lata nov. gen. & sp. (figs. 1 — 2). Cranidia. 



„ XI. Kjerulfia lata nov. gen. & sp. (figs. 1—3). Cranidium, hypostome and posterior 



thoracic segments with pygidium. 

 „ XII. Kjerulfia lata nov. gen. & sp. (figs, i— 5I. Hypostome, eye, genal spine and 



thoracic segments. 

 „ XIII. Kjerulfia lata nov. gen. & sp. (figs. 1 — 3. Thoracic segments and pygidium. 

 „ XIV. Kjerulfia lata nov. gen. & sp. (figs, i— 21. Sculpture. Holmia Kjerulfi Lnrs. 



(fig. 3-1. Sculpture. 



