Pl. V.

Megalaspis attenuata Wahlenb.

Fig. 1. Horizontal section of cephalic eye near the inferior margin 60/1. a surface of the eye, b frame with irregular or reserve prisms, c part of the cheek with normal structure. Spec. DP. » 2. Hypostoma 2/1. Spec. BM. » 3. The right macula 12/1. » 4. Part of the same in transmitted light 60/1. Spec. DR. » 5. Vertical (sagittal) section of the inferior part of the hypostoma, crossing the macula a 12/1. » 6. Vertical section of the same macula 60/1. All spec. from Westanå, Östergötland.

Megalaspis limbata Boeck p. 61.

Fig. 7. Hypostoma, mostly decorticated 2/1. Specimen from Fogelsång, Scania, the same as Brögger's original to his fig. 23.

Megalaspis planilimbata Angel. p. 61.

Fig. 8. Hypostoma, Öland, Äleklinta 2/1.

Megalaspis sp.

Fig. 9. Vertical section of macula (a) 12/1. Öland, Lower grey Orthoc. limestone.

Nileus armadillo Dalm. p. 62.

Fig. 10. Horizontal section of cephalic eye 60/1. » 11. Vertical section of the same 60/1. » 12. A similar section 60/1. a the prisms of clear calcareous spar, b the surface of the eye and the free cheek of yellow spar. » 13. The hypostoma 2/1. » 14. The right macula 12/1. » 15. Vertical section of macula (a) 12/1. All specimens from Persnäs, Öland, excepting fig. 13 from Westanå, Östergötland.

Symphysurus palpebrosus Dalman p. 62.

Fig. 16. Horizontal section of cephalic eye 60/1. » 17. Vertical section of the same 60/1. » 18. Hypostoma 2/1. From Westanå, Östergötland.

Niobe frontalis Ang. p. 63.

Fig. 19. The hypostoma 2/1. » 20. The right macula 10/1. » 21. Part of the same in transmitted light 60/1. Specimen from Kungs Norrby, Östergötland.

Niobe læviceps Ang. p. 63.

Fig. 22. Horizontal section of cephalic eye near the inferior margin, a cheek 60/1. » 23. Hypostoma 2/1. » 24. The right macula 10/1. » 23. Part of the same in transmitted light 60/1. » 26. Vertical section of macula a 12/1.

Ogygia dilatata var. Sarsi Angel. p. 63.

Fig. 27. Hypostoma 2/1. » 28. The right macula 10/1. From Christiania, Haakavik, Collection of Dr. G. Holm.

Olenus sp. p. 33.

Fig. 29. A part of the free cheek with the scallop 6/1. » 30. Profile of the scallop. Andrarum, Scania.

Parabolina spinulosa Wahlenb. p. 33.

Fig. 31. The free cheek with the scallop 3/1. » 32. Profile of the scallop. From Jemtland.

Paradoxides oelandicus Angel. p. 64.

Fig. 33. Hypostoma 2/1. » 34. The left macula 12/1. Öland, Torp.

Phacops cephalotes Barr. p. 65.

Fig. 35. The hypostoma; the shell mostly decorticated and the maculæ visible as casts on the inside. » 36. Cast of the inside of the right macula 12/1. Spec. from Lochkow, Bohemia.

Phacops quadrilineata Angel. p. 66.

Fig. 37. Horizontal section of cephalic eye near the inferior margin 30/1. The dark points lie in the outermost stratum of the cheek. » 38. Vertical section of cephalic eye 20/1. An irregularly hexaedral crystal below each lens. Specimen from Wisby a.

K. Sv. Vet. Akad. Handl., Bd 34, No 8. Lindström: Trilobites. Pl. V.

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G. Liljevall del. Ljustryck af Chr. Westphal Stockholm.