84 



LINDSTRÖM, VISUM, ORGANS OF THE TRILOBITES. 



Pl. V. 



Megalaspis attenuata WAHL1NB. p. 61. 



Fig. 1. Horizontal section of cephalic eye near the 

 inferior margin ,;u i. a surface of the eye, 

 A frame with irregular or reserve prisms, 

 c part of the check with normal structure. 

 Spec. DP. 



Fig. 



Fig. 



2. 

 3. 



4. 



5. 



Hypostoma 71. Spec. HM. 

 The right macula '- 1. 



Part of the same in transmitted light 60 /i. 

 Spec. DR. 



Vertical (sagittal) section of the inferior part 

 of the hypostoma, crossing the macula a 12 1. 

 7. Vertical section of the same macula ,; " 1. 

 All spec. from Westanå, Östergötland. 



Megalaspis limbata BOECK p. 61. 



7. Hypostoma, mostly decorticated V 1 - Speci- 

 men from Fogelsång, Scania, the same as 

 BrÖugerV original to his tig. 23. 



Megalaspis planilimbata ÄNGEL, p. 61. 



Fig. s. Hypostoma, Oland, Äleklinta 2 /i. 



Megalaspis sp. 



Fig. 9. Vertical section of macula (a) 1 - t. Öland, 

 •Lower grev Ortlioc. limestone. 



Nileus armadillo Dalm. p. 62. 



Horizontal section of cephalic eye ,; " 1. 



Vertical section of the same 60 /i. 



A similar section ,;o 1. a the prisms of clear 



ealcareous spar, b the surface of the eye and 



the free cheek of yellow spar. 



The hypostoma 2 /i. 



14. The right macula 12 /i. 



15. Vertical section of macula (a) n /i. All spe- 

 cimens from Persnäs, Oland, excepting fig. 

 13 from Westanå, Östergötland. 



Symphysurus palpebrosus Dalman p. 62. 



10. 

 11. 

 12. 



13 



Fii 



1C. 

 17. 



Horizontal section of cephalic eye i; " 1 

 Vertical section of the same 60 /i 



is. Hypostoma 2 /i. From Westanå, Östergötland. 



Niobe frontalis Ang. p. 63. 



Fig. 19. The hypostoma 2 /i. 

 » 2(>. The right macula 10 /i. 



21. Part of the same in transmitted light 6 %. 

 Specimen from Kungs Norrby, Östergötland. 



Niobe laeviceps Ang. p. 63. 



Fig. 22. Horizontal section of cephalic eye near the 

 inferior margin, a cheek 60 1. 

 » 23. Hypostoma 71 ■ 

 » 24. The right macula 10 /i. 

 » 25. Part of the same in transmitted light i; " 1. 

 26. Vertical section of macula a 12 1. 



Ogygia dilatata var. Sarsi ÄNGEL, p, 63. 



Fig. 27. Hypostoma 2 /i. 



28. The right macula t0 /i. From Ohristiania, 

 Haakavik, Collection of Dr. G. HOLM. 



Olenus sp. p. 33. 



Fig. 29. A part of the free cheek with the scallop i; 1. 

 30. Profile of the scallop. Andrarmn. 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 Ängel. p. 64. 



Fig. 33. Hypostoma 2 1. 

 » 34. The lett macula 12 1. Oland. Torp. 



Phacops cephalotes I!arr. p. 65. 



Fig. 35. The hypostoma; the shell mostly decorticated 

 and the macuke visihle as casts 011 the inside. 

 » 36. Oast of the inside of the right maeula 12 1. 

 Spec. from Lochkow, liohemia. 



Phacops quadrilineata ÅNGEL. i>. (i(i. 



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 -'" 1. An ir- 

 regularly hexaedral cristal below each lens. 

 Specimen from Wishy a. 



