Part 26

Fig. 50. The hypostoma 1/1. » 51. The left macula. Transparent lenses? 12/1. From the Leptæna limestone of Dalecarlia.

=Trochurus pusillus= ANG. p. 70.

Fig. 52. The hypostoma 5/1. » 53. The right macula in transmitted light. Seen from the inside 60/1. From Fröjel.

=Trochurus?= p. 70.

Fig. 54. The hypostoma 3/1. » 55. The right macula from the inside 12/1. From När Gotland.

K. Sv. Vet. Akad. Handl., Bd 34, No 8.

Lindström: Trilobites. IV.

G. Liljevall del.

Ljustryck af Chr. Westphal Stockholm.

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.