86 



LINDSTRÖM, VISUAL ORGANS OF THE TRILOBITES. 



Pl. VI. 



Phaeops macrophthalmus Burm. p. 65. 

 Fig. 1. Horizontal section of the cephalic eye 30 i. 



2. A similar one near the interiör margin, a 

 cheek 30 i. 



3. Vertical section of a cephalic eye :1 " i. 



4. A similar, twice as much enlarged 60 i. 



5. Also a similar, a cheek 30 i. 

 » 6. Hypostoma - i. Spec. EA. 



7. The wings of the hypostoma, seen vvithout 



foreshortcning 4 i. EA. 

 » 8. The diminutive right macula 12 i, surrounded 



by incoherent terrace lines. 

 9. The left macula 12 /i. Specimens from Gerol- 



stein Eifel, Devon. 



Acaste sp.? ]). 51. 

 Fig. 10. The hypostoma s i. From Mnlde, Fröjel, 

 Gotland. 



Phaétonides Stokesi Murch. p. 66. 



Hypostoma 4 /i. Gotland, Eksta, Djupvik. 



Phillipsia sp. p. 66. 

 A portion of the cephalic eye 2 " i. 

 The hypostoma 4 i. 



Fig. 

 Fig. 



Fig. 



Fig. 



Fig. 



11. 



12. 

 13. 

 14. 



The right macula 



Specimen from Beeren 



15. 



16. 

 17. 

 18. 



Fig. 19. 



60 



20. 



21. 



22. 

 23. 



24. 

 25. 



•26. 



Eiland, Oswalds förberg, communicated by 

 Hr. J. G. Andersson. 



Phillipsia sp.? p. 66. 

 The hypostoma 3 i. 

 The right macula ls /i. 

 Horizontal section of the cephalic eye 

 Vertical section of the cephalic eye, a cheek 

 60 i. Probably from the Carbon of Belgium. 



Proetus concinnus Dalm. p. 67. 

 Horizontal section of the cephalic eye, a little 

 oblique, at right the innermost stratum with 

 the rock 6 %. 



Vertical section of the cephalic eye. The 

 diameter of the prisms 0,oi! millim. 



Fig. 24 from Öja, Gotland, tlie others from 

 Kräklingbo. 



Proetus signatus LDM. p. 68. 

 27. Hypostoma ' i. 



28 — 30. Three pair of maculae with dark ocelli 

 in a wbite spöt. 



1I\ postoma 



The right macula 12 i. 



The same with a light, transparent spöt '- i. 



Specimen from Djup vi k, Eksta. 



Proetus conspersus Ang. p. 68. 



A portion of the cephalic eye 2 %. 



The hypostoma. Cast of the interiör side 4 i. 



Gast of the interiör side of the left macula 



Fiff. 



Ptyehopyge angustifrons Dalm. p. 69. 



31. Horizontal section of the cephalic eye 250 i. 



32. Hypostoma, a broad variety x i. 



33. Another, a narrow variety \ i. 



34. The left macula of the hypostoma fig. 32 4 i. 



35. A similar of the narrow variety 4 i. 



36. Vertical section of a macula. 



20 , 



a the macula 



Specimens from Vestanå and Kungs Norrby, 

 Östergötland. 



Ptyehopyge eineta Brögger p. 6!) 



(aceording to Fr. Schmidt. The flgure 12 a of Brögger re- 



sembles, however, the hypostoma of Pt. angustifrons, but not 



tlie hypostomata which have been prepared from the 



Ptych. eineta). 



Fig. 37. A hypostoma; the macula» are directed ob- 

 liquely - i. 

 » 38. The right macula of another specimen 4 i. 

 » 39. Vertical section of a macula G0 i. Specimens 

 from Kungs Norrby, Östergötland. 



Ptyehopyge acieulata Ang. p. 68. 

 (Compare Brögger II Taf. I, fig. 13.) 



Fig. 40. The hypostoma, cast of the interiör surface 

 1 i. 

 » 41. Cast of the right macula 4 i. Specimen from 

 Öland, Brunnby. 



Ptyehopyge glabrata Ang. p. 



Fig. 42. Original of Brogger's fig. 14. 

 inside of the right macula 4 i. 



69. 



Cast of the 

 Alleberg. 



Elyx laticeps Ang. p. 19. 

 Fig. 43. The interiör surface of the right fixed cheek 

 and the glabella. Magnified. Specimen from 

 Andrarum. 4 i. 



Conoeoryphe p. 19. 



Fig. 44. Cast of the interiör surface of the left cheek. 

 Magnified. From Andrarum. 4 i. 



Solenopleura brachymetopa ÄNGEL. p. 19. 

 Fig. 45. The head shield, cast of the interiör surface. 

 Magnified. Specimen from Andrarum, Sca- 

 nia. 4 i. 



Apus cancriformis ScHÄFFER p. 73. 

 Fig. 46. The hypostoma from the outside 8 i. 

 » 47. The same from the inside s i. 

 » 48. A side view of tbe same, 8 i. a the dupli- 



cature of the head shield, b posterior in- 



tegument of the hypostoma, c the ventriele, 



d the motith. 

 » 49. The right white spöt at the posterior margin 



of the hypostoma, seen from the outside in 



transmitted light ir>0 i. 



